diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index 51d25ba6..468fb14a 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -66,6 +66,9 @@ jobs:
       - name: Install Node dependencies
         run: |
           npm install -g markdownlint-cli jshint csslint
+      - name: Check with black
+        if: always()
+        run: python -m tox -e black && git diff --exit-code
       - name: Check with flake8
         if: always()
         run: python -m tox -e flake8
diff --git a/mkdocs/__main__.py b/mkdocs/__main__.py
index b4d77304..7e603e33 100644
--- a/mkdocs/__main__.py
+++ b/mkdocs/__main__.py
@@ -51,7 +51,7 @@ class ColorFormatter(logging.Formatter):
         'CRITICAL': 'red',
         'ERROR': 'red',
         'WARNING': 'yellow',
-        'DEBUG': 'blue'
+        'DEBUG': 'blue',
     }
 
     text_wrapper = textwrap.TextWrapper(
@@ -59,8 +59,8 @@ class ColorFormatter(logging.Formatter):
         replace_whitespace=False,
         break_long_words=False,
         break_on_hyphens=False,
-        initial_indent=' '*12,
-        subsequent_indent=' '*12
+        initial_indent=' ' * 12,
+        subsequent_indent=' ' * 12,
     )
 
     def format(self, record):
@@ -70,17 +70,14 @@ class ColorFormatter(logging.Formatter):
             prefix = click.style(prefix, fg=self.colors[record.levelname])
         if self.text_wrapper.width:
             # Only wrap text if a terminal width was detected
-            msg = '\n'.join(
-                self.text_wrapper.fill(line)
-                for line in message.splitlines()
-            )
+            msg = '\n'.join(self.text_wrapper.fill(line) for line in message.splitlines())
             # Prepend prefix after wrapping so that color codes don't affect length
             return prefix + msg[12:]
         return prefix + message
 
 
 class State:
-    ''' Maintain logging level.'''
+    """Maintain logging level."""
 
     def __init__(self, log_name='mkdocs', level=logging.INFO):
         self.logger = logging.getLogger(log_name)
@@ -99,34 +96,42 @@ pass_state = click.make_pass_decorator(State, ensure=True)
 
 clean_help = "Remove old files from the site_dir before building (the default)."
 config_help = "Provide a specific MkDocs config"
-dev_addr_help = ("IP address and port to serve documentation locally (default: "
-                 "localhost:8000)")
-strict_help = ("Enable strict mode. This will cause MkDocs to abort the build "
-               "on any warnings.")
+dev_addr_help = "IP address and port to serve documentation locally (default: localhost:8000)"
+strict_help = "Enable strict mode. This will cause MkDocs to abort the build on any warnings."
 theme_help = "The theme to use when building your documentation."
 theme_choices = utils.get_theme_names()
 site_dir_help = "The directory to output the result of the documentation build."
 use_directory_urls_help = "Use directory URLs when building pages (the default)."
 reload_help = "Enable the live reloading in the development server (this is the default)"
 no_reload_help = "Disable the live reloading in the development server."
-dirty_reload_help = "Enable the live reloading in the development server, but only re-build files that have changed"
-commit_message_help = ("A commit message to use when committing to the "
-                       "GitHub Pages remote branch. Commit {sha} and MkDocs {version} are available as expansions")
-remote_branch_help = ("The remote branch to commit to for GitHub Pages. This "
-                      "overrides the value specified in config")
-remote_name_help = ("The remote name to commit to for GitHub Pages. This "
-                    "overrides the value specified in config")
+dirty_reload_help = (
+    "Enable the live reloading in the development server, but only re-build files that have changed"
+)
+commit_message_help = (
+    "A commit message to use when committing to the "
+    "GitHub Pages remote branch. Commit {sha} and MkDocs {version} are available as expansions"
+)
+remote_branch_help = (
+    "The remote branch to commit to for GitHub Pages. This "
+    "overrides the value specified in config"
+)
+remote_name_help = (
+    "The remote name to commit to for GitHub Pages. This overrides the value specified in config"
+)
 force_help = "Force the push to the repository."
 no_history_help = "Replace the whole Git history with one new commit."
-ignore_version_help = "Ignore check that build is not being deployed with an older version of MkDocs."
-watch_theme_help = ("Include the theme in list of files to watch for live reloading. "
-                    "Ignored when live reload is not used.")
+ignore_version_help = (
+    "Ignore check that build is not being deployed with an older version of MkDocs."
+)
+watch_theme_help = (
+    "Include the theme in list of files to watch for live reloading. "
+    "Ignored when live reload is not used."
+)
 shell_help = "Use the shell when invoking Git."
-watch_help = ("A directory or file to watch for live reloading. "
-              "Can be supplied multiple times.")
+watch_help = "A directory or file to watch for live reloading. Can be supplied multiple times."
 
 
-def add_options(opts):
+def add_options(*opts):
     def inner(f):
         for i in reversed(opts):
             f = i(f)
@@ -140,11 +145,15 @@ def verbose_option(f):
         state = ctx.ensure_object(State)
         if value:
             state.stream.setLevel(logging.DEBUG)
-    return click.option('-v', '--verbose',
-                        is_flag=True,
-                        expose_value=False,
-                        help='Enable verbose output',
-                        callback=callback)(f)
+
+    return click.option(
+        '-v',
+        '--verbose',
+        is_flag=True,
+        expose_value=False,
+        help='Enable verbose output',
+        callback=callback,
+    )(f)
 
 
 def quiet_option(f):
@@ -152,15 +161,19 @@ def quiet_option(f):
         state = ctx.ensure_object(State)
         if value:
             state.stream.setLevel(logging.ERROR)
-    return click.option('-q', '--quiet',
-                        is_flag=True,
-                        expose_value=False,
-                        help='Silence warnings',
-                        callback=callback)(f)
+
+    return click.option(
+        '-q',
+        '--quiet',
+        is_flag=True,
+        expose_value=False,
+        help='Silence warnings',
+        callback=callback,
+    )(f)
 
 
-common_options = add_options([quiet_option, verbose_option])
-common_config_options = add_options([
+common_options = add_options(quiet_option, verbose_option)
+common_config_options = add_options(
     click.option('-f', '--config-file', type=click.File('rb'), help=config_help),
     # Don't override config value if user did not specify --strict flag
     # Conveniently, load_config drops None values
@@ -168,8 +181,13 @@ common_config_options = add_options([
     click.option('-t', '--theme', type=click.Choice(theme_choices), help=theme_help),
     # As with --strict, set the default to None so that this doesn't incorrectly
     # override the config file
-    click.option('--use-directory-urls/--no-directory-urls', is_flag=True, default=None, help=use_directory_urls_help)
-])
+    click.option(
+        '--use-directory-urls/--no-directory-urls',
+        is_flag=True,
+        default=None,
+        help=use_directory_urls_help,
+    ),
+)
 
 PYTHON_VERSION = f"{sys.version_info.major}.{sys.version_info.minor}"
 
@@ -179,8 +197,9 @@ PKG_DIR = os.path.dirname(os.path.abspath(__file__))
 @click.group(context_settings={'help_option_names': ['-h', '--help']})
 @click.version_option(
     __version__,
-    '-V', '--version',
-    message=f'%(prog)s, version %(version)s from { PKG_DIR } (Python { PYTHON_VERSION })'
+    '-V',
+    '--version',
+    message=f'%(prog)s, version %(version)s from { PKG_DIR } (Python { PYTHON_VERSION })',
 )
 @common_options
 def cli():
@@ -195,12 +214,15 @@ def cli():
 @click.option('--no-livereload', 'livereload', flag_value='no-livereload', help=no_reload_help)
 @click.option('--dirtyreload', 'livereload', flag_value='dirty', help=dirty_reload_help)
 @click.option('--watch-theme', help=watch_theme_help, is_flag=True)
-@click.option('-w', '--watch', help=watch_help, type=click.Path(exists=True), multiple=True, default=[])
+@click.option(
+    '-w', '--watch', help=watch_help, type=click.Path(exists=True), multiple=True, default=[]
+)
 @common_config_options
 @common_options
 def serve_command(dev_addr, livereload, watch, **kwargs):
     """Run the builtin development server"""
     from mkdocs.commands import serve
+
     _enable_warnings()
     serve.serve(dev_addr=dev_addr, livereload=livereload, watch=watch, **kwargs)
 
@@ -213,6 +235,7 @@ def serve_command(dev_addr, livereload, watch, **kwargs):
 def build_command(clean, **kwargs):
     """Build the MkDocs documentation"""
     from mkdocs.commands import build
+
     _enable_warnings()
     build.build(config.load_config(**kwargs), dirty=not clean)
 
@@ -229,15 +252,14 @@ def build_command(clean, **kwargs):
 @common_config_options
 @click.option('-d', '--site-dir', type=click.Path(), help=site_dir_help)
 @common_options
-def gh_deploy_command(clean, message, remote_branch, remote_name, force, no_history, ignore_version, shell, **kwargs):
+def gh_deploy_command(
+    clean, message, remote_branch, remote_name, force, no_history, ignore_version, shell, **kwargs
+):
     """Deploy your documentation to GitHub Pages"""
     from mkdocs.commands import build, gh_deploy
+
     _enable_warnings()
-    cfg = config.load_config(
-        remote_branch=remote_branch,
-        remote_name=remote_name,
-        **kwargs
-    )
+    cfg = config.load_config(remote_branch=remote_branch, remote_name=remote_name, **kwargs)
     build.build(cfg, dirty=not clean)
     gh_deploy.gh_deploy(
         cfg,
@@ -245,7 +267,7 @@ def gh_deploy_command(clean, message, remote_branch, remote_name, force, no_hist
         force=force,
         no_history=no_history,
         ignore_version=ignore_version,
-        shell=shell
+        shell=shell,
     )
 
 
@@ -255,6 +277,7 @@ def gh_deploy_command(clean, message, remote_branch, remote_name, force, no_hist
 def new_command(project_directory):
     """Create a new MkDocs project"""
     from mkdocs.commands import new
+
     new.new(project_directory)
 
 
diff --git a/mkdocs/commands/babel.py b/mkdocs/commands/babel.py
index bbfa9e82..0cdbbada 100644
--- a/mkdocs/commands/babel.py
+++ b/mkdocs/commands/babel.py
@@ -4,14 +4,14 @@ from pkg_resources import EntryPoint
 from babel.messages import frontend as babel
 
 
-DEFAULT_MAPPING_FILE = path.normpath(path.join(
-    path.abspath(path.dirname(__file__)), '../themes/babel.cfg'
-))
+DEFAULT_MAPPING_FILE = path.normpath(
+    path.join(path.abspath(path.dirname(__file__)), '../themes/babel.cfg')
+)
 
 
 class ThemeMixin:
     def get_theme_dir(self):
-        ''' Validate theme option and return path to theme's root obtained from entry point. '''
+        """Validate theme option and return path to theme's root obtained from entry point."""
         entry_points = EntryPoint.parse_map(self.distribution.entry_points, self.distribution)
         if 'mkdocs.themes' not in entry_points:
             raise DistutilsOptionError("no mkdocs.themes are defined in entry_points")
diff --git a/mkdocs/commands/build.py b/mkdocs/commands/build.py
index 144c6230..b191aac2 100644
--- a/mkdocs/commands/build.py
+++ b/mkdocs/commands/build.py
@@ -14,7 +14,8 @@ import mkdocs
 
 
 class DuplicateFilter:
-    ''' Avoid logging duplicate messages. '''
+    """Avoid logging duplicate messages."""
+
     def __init__(self):
         self.msgs = set()
 
@@ -46,15 +47,11 @@ def get_context(nav, files, config, page=None, base_url=''):
     return {
         'nav': nav,
         'pages': files,
-
         'base_url': base_url,
-
         'extra_css': extra_css,
         'extra_javascript': extra_javascript,
-
         'mkdocs_version': mkdocs.__version__,
         'build_date_utc': utils.get_build_datetime(),
-
         'config': config,
         'page': page,
     }
@@ -90,15 +87,13 @@ def _build_template(name, template, files, config, nav):
     output = template.render(context)
 
     # Run `post_template` plugin events.
-    output = config['plugins'].run_event(
-        'post_template', output, template_name=name, config=config
-    )
+    output = config['plugins'].run_event('post_template', output, template_name=name, config=config)
 
     return output
 
 
 def _build_theme_template(template_name, env, files, config, nav):
-    """ Build a template using the theme environment. """
+    """Build a template using the theme environment."""
 
     log.debug(f"Building theme template: {template_name}")
 
@@ -119,14 +114,16 @@ def _build_theme_template(template_name, env, files, config, nav):
             gz_filename = f'{output_path}.gz'
             with open(gz_filename, 'wb') as f:
                 timestamp = utils.get_build_timestamp()
-                with gzip.GzipFile(fileobj=f, filename=gz_filename, mode='wb', mtime=timestamp) as gz_buf:
+                with gzip.GzipFile(
+                    fileobj=f, filename=gz_filename, mode='wb', mtime=timestamp
+                ) as gz_buf:
                     gz_buf.write(output.encode('utf-8'))
     else:
         log.info(f"Template skipped: '{template_name}' generated empty output.")
 
 
 def _build_extra_template(template_name, files, config, nav):
-    """ Build user templates which are not part of the theme. """
+    """Build user templates which are not part of the theme."""
 
     log.debug(f"Building extra template: {template_name}")
 
@@ -151,7 +148,7 @@ def _build_extra_template(template_name, files, config, nav):
 
 
 def _populate_page(page, config, files, dirty=False):
-    """ Read page content from docs_dir and render Markdown. """
+    """Read page content from docs_dir and render Markdown."""
 
     try:
         # When --dirty is used, only read the page if the file has been modified since the
@@ -160,9 +157,7 @@ def _populate_page(page, config, files, dirty=False):
             return
 
         # Run the `pre_page` plugin event
-        page = config['plugins'].run_event(
-            'pre_page', page, config=config, files=files
-        )
+        page = config['plugins'].run_event('pre_page', page, config=config, files=files)
 
         page.read_source(config)
 
@@ -187,7 +182,7 @@ def _populate_page(page, config, files, dirty=False):
 
 
 def _build_page(page, config, doc_files, nav, env, dirty=False):
-    """ Pass a Page to theme template and write output to site_dir. """
+    """Pass a Page to theme template and write output to site_dir."""
 
     try:
         # When --dirty is used, only build the page if the file has been modified since the
@@ -217,13 +212,13 @@ def _build_page(page, config, doc_files, nav, env, dirty=False):
         output = template.render(context)
 
         # Run `post_page` plugin events.
-        output = config['plugins'].run_event(
-            'post_page', output, page=page, config=config
-        )
+        output = config['plugins'].run_event('post_page', output, page=page, config=config)
 
         # Write the output file.
         if output.strip():
-            utils.write_file(output.encode('utf-8', errors='xmlcharrefreplace'), page.file.abs_dest_path)
+            utils.write_file(
+                output.encode('utf-8', errors='xmlcharrefreplace'), page.file.abs_dest_path
+            )
         else:
             log.info(f"Page skipped: '{page.file.src_path}'. Generated empty output.")
 
@@ -239,7 +234,7 @@ def _build_page(page, config, doc_files, nav, env, dirty=False):
 
 
 def build(config, live_server=False, dirty=False):
-    """ Perform a full site build. """
+    """Perform a full site build."""
 
     logger = logging.getLogger('mkdocs')
 
@@ -251,6 +246,7 @@ def build(config, live_server=False, dirty=False):
 
     try:
         from time import time
+
         start = time()
 
         # Run `config` plugin events.
@@ -264,8 +260,10 @@ def build(config, live_server=False, dirty=False):
             utils.clean_directory(config['site_dir'])
         else:  # pragma: no cover
             # Warn user about problems that may occur with --dirty option
-            log.warning("A 'dirty' build is being performed, this will likely lead to inaccurate navigation and other"
-                        " links within your site. This option is designed for site development purposes only.")
+            log.warning(
+                "A 'dirty' build is being performed, this will likely lead to inaccurate navigation and other"
+                " links within your site. This option is designed for site development purposes only."
+            )
 
         if not live_server:  # pragma: no cover
             log.info(f"Building documentation to directory: {config['site_dir']}")
@@ -292,9 +290,7 @@ def build(config, live_server=False, dirty=False):
             _populate_page(file.page, config, files, dirty)
 
         # Run `env` plugin events.
-        env = config['plugins'].run_event(
-            'env', env, config=config, files=files
-        )
+        env = config['plugins'].run_event('env', env, config=config, files=files)
 
         # Start writing files to site_dir now that all data is gathered. Note that order matters. Files
         # with lower precedence get written first so that files with higher precedence can overwrite them.
@@ -336,6 +332,6 @@ def build(config, live_server=False, dirty=False):
 
 
 def site_directory_contains_stale_files(site_directory):
-    """ Check if the site directory contains stale files from a previous build. """
+    """Check if the site directory contains stale files from a previous build."""
 
     return True if os.path.exists(site_directory) and os.listdir(site_directory) else False
diff --git a/mkdocs/commands/gh_deploy.py b/mkdocs/commands/gh_deploy.py
index 2748447e..4b754e43 100644
--- a/mkdocs/commands/gh_deploy.py
+++ b/mkdocs/commands/gh_deploy.py
@@ -18,7 +18,7 @@ def _is_cwd_git_repo():
         proc = subprocess.Popen(
             ['git', 'rev-parse', '--is-inside-work-tree'],
             stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE
+            stderr=subprocess.PIPE,
         )
     except FileNotFoundError:
         log.error("Could not find git - is it installed and on your path?")
@@ -29,8 +29,12 @@ def _is_cwd_git_repo():
 
 def _get_current_sha(repo_path):
 
-    proc = subprocess.Popen(['git', 'rev-parse', '--short', 'HEAD'], cwd=repo_path or None,
-                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    proc = subprocess.Popen(
+        ['git', 'rev-parse', '--short', 'HEAD'],
+        cwd=repo_path or None,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
 
     stdout, _ = proc.communicate()
     sha = stdout.decode('utf-8').strip()
@@ -42,8 +46,11 @@ def _get_remote_url(remote_name):
     # No CNAME found.  We will use the origin URL to determine the GitHub
     # pages location.
     remote = f"remote.{remote_name}.url"
-    proc = subprocess.Popen(["git", "config", "--get", remote],
-                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    proc = subprocess.Popen(
+        ["git", "config", "--get", remote],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
 
     stdout, _ = proc.communicate()
     url = stdout.decode('utf-8').strip()
@@ -60,8 +67,11 @@ def _get_remote_url(remote_name):
 
 def _check_version(branch):
 
-    proc = subprocess.Popen(['git', 'show', '-s', '--format=%s', f'refs/heads/{branch}'],
-                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    proc = subprocess.Popen(
+        ['git', 'show', '-s', '--format=%s', f'refs/heads/{branch}'],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
 
     stdout, _ = proc.communicate()
     msg = stdout.decode('utf-8').strip()
@@ -84,11 +94,12 @@ def _check_version(branch):
         raise Abort('Deployment Aborted!')
 
 
-def gh_deploy(config, message=None, force=False, no_history=False, ignore_version=False, shell=False):
+def gh_deploy(
+    config, message=None, force=False, no_history=False, ignore_version=False, shell=False
+):
 
     if not _is_cwd_git_repo():
-        log.error('Cannot deploy - this directory does not appear to be a git '
-                  'repository')
+        log.error('Cannot deploy - this directory does not appear to be a git repository')
 
     remote_branch = config['remote_branch']
     remote_name = config['remote_name']
@@ -101,8 +112,11 @@ def gh_deploy(config, message=None, force=False, no_history=False, ignore_versio
     sha = _get_current_sha(os.path.dirname(config.config_file_path))
     message = message.format(version=mkdocs.__version__, sha=sha)
 
-    log.info("Copying '%s' to '%s' branch and pushing to GitHub.",
-             config['site_dir'], config['remote_branch'])
+    log.info(
+        "Copying '%s' to '%s' branch and pushing to GitHub.",
+        config['site_dir'],
+        config['remote_branch'],
+    )
 
     try:
         ghp_import.ghp_import(
@@ -114,7 +128,7 @@ def gh_deploy(config, message=None, force=False, no_history=False, ignore_versio
             force=force,
             use_shell=shell,
             no_history=no_history,
-            nojekyll=True
+            nojekyll=True,
         )
     except ghp_import.GhpError as e:
         log.error(f"Failed to deploy to GitHub with error: \n{e.message}")
@@ -126,10 +140,13 @@ def gh_deploy(config, message=None, force=False, no_history=False, ignore_versio
         # This GitHub pages repository has a CNAME configured.
         with open(cname_file) as f:
             cname_host = f.read().strip()
-        log.info(f'Based on your CNAME file, your documentation should be '
-                 f'available shortly at: http://{cname_host}')
-        log.info('NOTE: Your DNS records must be configured appropriately for '
-                 'your CNAME URL to work.')
+        log.info(
+            f'Based on your CNAME file, your documentation should be '
+            f'available shortly at: http://{cname_host}'
+        )
+        log.info(
+            'NOTE: Your DNS records must be configured appropriately for your CNAME URL to work.'
+        )
         return
 
     host, path = _get_remote_url(remote_name)
@@ -140,6 +157,6 @@ def gh_deploy(config, message=None, force=False, no_history=False, ignore_versio
     else:
         username, repo = path.split('/', 1)
         if repo.endswith('.git'):
-            repo = repo[:-len('.git')]
+            repo = repo[: -len('.git')]
         url = f'https://{username}.github.io/{repo}/'
         log.info(f"Your documentation should shortly be available at: {url}")
diff --git a/mkdocs/commands/serve.py b/mkdocs/commands/serve.py
index fec06fa2..b5cf1d58 100644
--- a/mkdocs/commands/serve.py
+++ b/mkdocs/commands/serve.py
@@ -14,8 +14,17 @@ from mkdocs.livereload import LiveReloadServer
 log = logging.getLogger(__name__)
 
 
-def serve(config_file=None, dev_addr=None, strict=None, theme=None,
-          theme_dir=None, livereload='livereload', watch_theme=False, watch=[], **kwargs):
+def serve(
+    config_file=None,
+    dev_addr=None,
+    strict=None,
+    theme=None,
+    theme_dir=None,
+    livereload='livereload',
+    watch_theme=False,
+    watch=[],
+    **kwargs,
+):
     """
     Start the MkDocs development server
 
@@ -41,7 +50,7 @@ def serve(config_file=None, dev_addr=None, strict=None, theme=None,
             theme=theme,
             theme_dir=theme_dir,
             site_dir=site_dir,
-            **kwargs
+            **kwargs,
         )
 
         # combine CLI watch arguments with config file values
@@ -63,7 +72,9 @@ def serve(config_file=None, dev_addr=None, strict=None, theme=None,
         config = builder()
 
         host, port = config['dev_addr']
-        server = LiveReloadServer(builder=builder, host=host, port=port, root=site_dir, mount_path=mount_path(config))
+        server = LiveReloadServer(
+            builder=builder, host=host, port=port, root=site_dir, mount_path=mount_path(config)
+        )
 
         def error_handler(code):
             if code in (404, 500):
diff --git a/mkdocs/commands/setup.py b/mkdocs/commands/setup.py
index b0512d0d..f68e3683 100644
--- a/mkdocs/commands/setup.py
+++ b/mkdocs/commands/setup.py
@@ -3,8 +3,9 @@ try:
         compile_catalog,
         extract_messages,
         init_catalog,
-        update_catalog
+        update_catalog,
     )
+
     babel_cmdclass = {
         'compile_catalog': compile_catalog,
         'extract_messages': extract_messages,
diff --git a/mkdocs/config/__init__.py b/mkdocs/config/__init__.py
index b9780de6..02827893 100644
--- a/mkdocs/config/__init__.py
+++ b/mkdocs/config/__init__.py
@@ -1,4 +1,3 @@
 from mkdocs.config.base import load_config, Config
 
-__all__ = [load_config.__name__,
-           Config.__name__]
+__all__ = [load_config.__name__, Config.__name__]
diff --git a/mkdocs/config/base.py b/mkdocs/config/base.py
index 8f7f8bef..74c23573 100644
--- a/mkdocs/config/base.py
+++ b/mkdocs/config/base.py
@@ -66,10 +66,8 @@ class Config(UserDict):
             except ValidationError as e:
                 failed.append((key, e))
 
-        for key in (set(self.keys()) - self._schema_keys):
-            warnings.append((
-                key, f"Unrecognised configuration name: {key}"
-            ))
+        for key in set(self.keys()) - self._schema_keys:
+            warnings.append((key, f"Unrecognised configuration name: {key}"))
 
         return failed, warnings
 
@@ -120,19 +118,20 @@ class Config(UserDict):
         return failed, warnings
 
     def load_dict(self, patch):
-        """ Load config options from a dictionary. """
+        """Load config options from a dictionary."""
 
         if not isinstance(patch, dict):
             raise exceptions.ConfigurationError(
                 "The configuration is invalid. The expected type was a key "
                 "value mapping (a python dict) but we got an object of type: "
-                f"{type(patch)}")
+                f"{type(patch)}"
+            )
 
         self.user_configs.append(patch)
         self.data.update(patch)
 
     def load_file(self, config_file):
-        """ Load config options from the open file descriptor of a YAML file. """
+        """Load config options from the open file descriptor of a YAML file."""
         try:
             return self.load_dict(utils.yaml_load(config_file))
         except YAMLError as e:
@@ -177,8 +176,7 @@ def _open_config_file(config_file):
             except FileNotFoundError:
                 continue
         else:
-            raise exceptions.ConfigurationError(
-                f"Config file '{paths_to_try[0]}' does not exist.")
+            raise exceptions.ConfigurationError(f"Config file '{paths_to_try[0]}' does not exist.")
     else:
         log.debug(f"Loading configuration file: {config_file}")
         # Ensure file descriptor is at beginning
@@ -214,6 +212,7 @@ def load_config(config_file=None, **kwargs):
 
         # Initialize the config with the default schema.
         from mkdocs.config.defaults import get_schema
+
         cfg = Config(schema=get_schema(), config_file_path=options['config_file_path'])
         # load the config file
         cfg.load_file(fd)
@@ -233,9 +232,7 @@ def load_config(config_file=None, **kwargs):
         log.debug(f"Config value: '{key}' = {value!r}")
 
     if len(errors) > 0:
-        raise exceptions.Abort(
-            f"Aborted with {len(errors)} Configuration Errors!"
-        )
+        raise exceptions.Abort(f"Aborted with {len(errors)} Configuration Errors!")
     elif cfg['strict'] and len(warnings) > 0:
         raise exceptions.Abort(
             f"Aborted with {len(warnings)} Configuration Warnings in 'strict' mode!"
diff --git a/mkdocs/config/config_options.py b/mkdocs/config/config_options.py
index 2074c7c0..5e654295 100644
--- a/mkdocs/config/config_options.py
+++ b/mkdocs/config/config_options.py
@@ -12,7 +12,6 @@ from mkdocs.config.base import Config, ValidationError
 
 
 class BaseConfigOption:
-
     def __init__(self):
         self.warnings = []
         self.default = None
@@ -72,6 +71,7 @@ class ConfigItems(BaseConfigOption):
     Validates a list of mappings that all must match the same set of
     options.
     """
+
     def __init__(self, *config_options, **kwargs):
         BaseConfigOption.__init__(self)
         self.item_config = SubConfig(*config_options)
@@ -88,8 +88,9 @@ class ConfigItems(BaseConfigOption):
                 return ()
 
         if not isinstance(value, Sequence):
-            raise ValidationError(f'Expected a sequence of mappings, but a '
-                                  f'{type(value)} was given.')
+            raise ValidationError(
+                f'Expected a sequence of mappings, but a ' f'{type(value)} was given.'
+            )
 
         return [self.item_config.validate(item) for item in value]
 
@@ -149,8 +150,10 @@ class Type(OptionallyRequired):
         if not isinstance(value, self._type):
             msg = f"Expected type: {self._type} but received: {type(value)}"
         elif self.length is not None and len(value) != self.length:
-            msg = (f"Expected type: {self._type} with length {self.length}"
-                   f" but received: {value} with length {len(value)}")
+            msg = (
+                f"Expected type: {self._type} with length {self.length}"
+                f" but received: {value} with length {len(value)}"
+            )
         else:
             return value
 
@@ -287,10 +290,10 @@ class IpAddress(OptionallyRequired):
         host = config[key_name].host
         if key_name == 'dev_addr' and host in ['0.0.0.0', '::']:
             self.warnings.append(
-                (f"The use of the IP address '{host}' suggests a production environment "
-                 "or the use of a proxy to connect to the MkDocs server. However, "
-                 "the MkDocs' server is intended for local development purposes only. "
-                 "Please use a third party production-ready server instead.")
+                f"The use of the IP address '{host}' suggests a production environment "
+                "or the use of a proxy to connect to the MkDocs server. However, "
+                "the MkDocs' server is intended for local development purposes only. "
+                "Please use a third party production-ready server instead."
             )
 
 
@@ -319,8 +322,7 @@ class URL(OptionallyRequired):
                 parsed_url = parsed_url._replace(path=f'{parsed_url.path}/')
             return urlunsplit(parsed_url)
 
-        raise ValidationError(
-            "The URL isn't valid, it should include the http:// (scheme)")
+        raise ValidationError("The URL isn't valid, it should include the http:// (scheme)")
 
 
 class RepoURL(URL):
@@ -373,7 +375,9 @@ class FilesystemObject(Type):
         self.config_dir = None
 
     def pre_validation(self, config, key_name):
-        self.config_dir = os.path.dirname(config.config_file_path) if config.config_file_path else None
+        self.config_dir = (
+            os.path.dirname(config.config_file_path) if config.config_file_path else None
+        )
 
     def run_validation(self, value):
         value = super().run_validation(value)
@@ -390,6 +394,7 @@ class Dir(FilesystemObject):
 
     Validate a path to a directory, optionally verifying that it exists.
     """
+
     existence_test = staticmethod(os.path.isdir)
     name = 'directory'
 
@@ -400,9 +405,10 @@ class Dir(FilesystemObject):
         # Validate that the dir is not the parent dir of the config file.
         if os.path.dirname(config.config_file_path) == config[key_name]:
             raise ValidationError(
-                (f"The '{key_name}' should not be the parent directory of the"
-                 " config file. Use a child directory instead so that the"
-                 f" '{key_name}' is a sibling of the config file."))
+                f"The '{key_name}' should not be the parent directory of the"
+                f" config file. Use a child directory instead so that the"
+                f" '{key_name}' is a sibling of the config file."
+            )
 
 
 class File(FilesystemObject):
@@ -411,6 +417,7 @@ class File(FilesystemObject):
 
     Validate a path to a file, optionally verifying that it exists.
     """
+
     existence_test = staticmethod(os.path.isfile)
     name = 'file'
 
@@ -427,7 +434,9 @@ class ListOfPaths(OptionallyRequired):
         super().__init__(default, required)
 
     def pre_validation(self, config, key_name):
-        self.config_dir = os.path.dirname(config.config_file_path) if config.config_file_path else None
+        self.config_dir = (
+            os.path.dirname(config.config_file_path) if config.config_file_path else None
+        )
 
     def run_validation(self, value):
         if not isinstance(value, list):
@@ -455,24 +464,26 @@ class SiteDir(Dir):
     def post_validation(self, config, key_name):
 
         super().post_validation(config, key_name)
+        docs_dir = config['docs_dir']
+        site_dir = config['site_dir']
 
         # Validate that the docs_dir and site_dir don't contain the
         # other as this will lead to copying back and forth on each
         # and eventually make a deep nested mess.
-        if (config['docs_dir'] + os.sep).startswith(config['site_dir'].rstrip(os.sep) + os.sep):
+        if (docs_dir + os.sep).startswith(site_dir.rstrip(os.sep) + os.sep):
             raise ValidationError(
-                ("The 'docs_dir' should not be within the 'site_dir' as this "
-                 "can mean the source files are overwritten by the output or "
-                 "it will be deleted if --clean is passed to mkdocs build."
-                 "(site_dir: '{}', docs_dir: '{}')"
-                 ).format(config['site_dir'], config['docs_dir']))
-        elif (config['site_dir'] + os.sep).startswith(config['docs_dir'].rstrip(os.sep) + os.sep):
+                f"The 'docs_dir' should not be within the 'site_dir' as this "
+                f"can mean the source files are overwritten by the output or "
+                f"it will be deleted if --clean is passed to mkdocs build."
+                f"(site_dir: '{site_dir}', docs_dir: '{docs_dir}')"
+            )
+        elif (site_dir + os.sep).startswith(docs_dir.rstrip(os.sep) + os.sep):
             raise ValidationError(
-                ("The 'site_dir' should not be within the 'docs_dir' as this "
-                 "leads to the build directory being copied into itself and "
-                 "duplicate nested files in the 'site_dir'."
-                 "(site_dir: '{}', docs_dir: '{}')"
-                 ).format(config['site_dir'], config['docs_dir']))
+                f"The 'site_dir' should not be within the 'docs_dir' as this "
+                f"leads to the build directory being copied into itself and "
+                f"duplicate nested files in the 'site_dir'."
+                f"(site_dir: '{site_dir}', docs_dir: '{docs_dir}')"
+            )
 
 
 class Theme(BaseConfigOption):
@@ -507,13 +518,17 @@ class Theme(BaseConfigOption):
 
             raise ValidationError("No theme name set.")
 
-        raise ValidationError(f'Invalid type "{type(value)}". Expected a string or key/value pairs.')
+        raise ValidationError(
+            f'Invalid type "{type(value)}". Expected a string or key/value pairs.'
+        )
 
     def post_validation(self, config, key_name):
         theme_config = config[key_name]
 
         if not theme_config['name'] and 'custom_dir' not in theme_config:
-            raise ValidationError("At least one of 'theme.name' or 'theme.custom_dir' must be defined.")
+            raise ValidationError(
+                "At least one of 'theme.name' or 'theme.custom_dir' must be defined."
+            )
 
         # Ensure custom_dir is an absolute path
         if 'custom_dir' in theme_config and not os.path.isabs(theme_config['custom_dir']):
@@ -521,8 +536,11 @@ class Theme(BaseConfigOption):
             theme_config['custom_dir'] = os.path.join(config_dir, theme_config['custom_dir'])
 
         if 'custom_dir' in theme_config and not os.path.isdir(theme_config['custom_dir']):
-            raise ValidationError("The path set in {name}.custom_dir ('{path}') does not exist.".
-                                  format(path=theme_config['custom_dir'], name=key_name))
+            raise ValidationError(
+                "The path set in {name}.custom_dir ('{path}') does not exist.".format(
+                    path=theme_config['custom_dir'], name=key_name
+                )
+            )
 
         if 'locale' in theme_config and not isinstance(theme_config['locale'], str):
             raise ValidationError(f"'{theme_config['name']}.locale' must be a string.")
@@ -559,11 +577,15 @@ class Nav(OptionallyRequired):
             pass
         elif isinstance(value, dict):
             if len(value) != 1:
-                raise ValidationError(f"Expected nav item to be a dict of size 1, got {self._repr_item(value)}")
+                raise ValidationError(
+                    f"Expected nav item to be a dict of size 1, got {self._repr_item(value)}"
+                )
             for subnav in value.values():
                 self.run_validation(subnav, top=False)
         else:
-            raise ValidationError(f"Expected nav item to be a string or dict, got {self._repr_item(value)}")
+            raise ValidationError(
+                f"Expected nav item to be a string or dict, got {self._repr_item(value)}"
+            )
 
     @classmethod
     def _repr_item(cls, value):
@@ -595,7 +617,8 @@ class MarkdownExtensions(OptionallyRequired):
     a dict item must be a valid Markdown extension name and the value must be a dict of config
     options for that extension. Extension configs are set on the private setting passed to
     `configkey`. The `builtins` keyword accepts a list of extensions which cannot be overridden by
-    the user. However, builtins can be duplicated to define config options for them if desired. """
+    the user. However, builtins can be duplicated to define config options for them if desired."""
+
     def __init__(self, builtins=None, configkey='mdx_configs', **kwargs):
         super().__init__(**kwargs)
         self.builtins = builtins or []
@@ -647,7 +670,9 @@ class MarkdownExtensions(OptionallyRequired):
                     stack.insert(0, frame)
                 tb = ''.join(traceback.format_list(stack))
 
-                raise ValidationError(f"Failed to load extension '{ext}'.\n{tb}{type(e).__name__}: {e}")
+                raise ValidationError(
+                    f"Failed to load extension '{ext}'.\n{tb}{type(e).__name__}: {e}"
+                )
 
         return extensions
 
@@ -705,15 +730,13 @@ class Plugins(OptionallyRequired):
         if not issubclass(Plugin, plugins.BasePlugin):
             raise ValidationError(
                 f'{Plugin.__module__}.{Plugin.__name__} must be a subclass of'
-                f' {plugins.BasePlugin.__module__}.{plugins.BasePlugin.__name__}')
+                f' {plugins.BasePlugin.__module__}.{plugins.BasePlugin.__name__}'
+            )
 
         plugin = Plugin()
         errors, warnings = plugin.load_config(config, self.config_file_path)
         self.warnings.extend(warnings)
-        errors_message = '\n'.join(
-            f"Plugin '{name}' value: '{x}'. Error: {y}"
-            for x, y in errors
-        )
+        errors_message = '\n'.join(f"Plugin '{name}' value: '{x}'. Error: {y}" for x, y in errors)
         if errors_message:
             raise ValidationError(errors_message)
         return plugin
diff --git a/mkdocs/config/defaults.py b/mkdocs/config/defaults.py
index 95d3c440..79f346d0 100644
--- a/mkdocs/config/defaults.py
+++ b/mkdocs/config/defaults.py
@@ -10,116 +10,91 @@ from mkdocs.config import config_options
 
 
 def get_schema():
-    return (
-
+    schema = {
         # Reserved for internal use, stores the mkdocs.yml config file.
-        ('config_file_path', config_options.Type(str)),
-
+        'config_file_path': config_options.Type(str),
         # The title to use for the documentation
-        ('site_name', config_options.Type(str, required=True)),
-
+        'site_name': config_options.Type(str, required=True),
         # Defines the structure of the navigation.
-        ('nav', config_options.Nav()),
-        ('pages', config_options.Deprecated(removed=True, moved_to='nav')),
-
+        'nav': config_options.Nav(),
+        'pages': config_options.Deprecated(removed=True, moved_to='nav'),
         # The full URL to where the documentation will be hosted
-        ('site_url', config_options.URL(is_dir=True)),
-
+        'site_url': config_options.URL(is_dir=True),
         # A description for the documentation project that will be added to the
         # HTML meta tags.
-        ('site_description', config_options.Type(str)),
+        'site_description': config_options.Type(str),
         # The name of the author to add to the HTML meta tags
-        ('site_author', config_options.Type(str)),
-
+        'site_author': config_options.Type(str),
         # The MkDocs theme for the documentation.
-        ('theme', config_options.Theme(default='mkdocs')),
-
+        'theme': config_options.Theme(default='mkdocs'),
         # The directory containing the documentation markdown.
-        ('docs_dir', config_options.Dir(default='docs', exists=True)),
-
+        'docs_dir': config_options.Dir(default='docs', exists=True),
         # The directory where the site will be built to
-        ('site_dir', config_options.SiteDir(default='site')),
-
+        'site_dir': config_options.SiteDir(default='site'),
         # A copyright notice to add to the footer of documentation.
-        ('copyright', config_options.Type(str)),
-
+        'copyright': config_options.Type(str),
         # set of values for Google analytics containing the account IO and domain,
         # this should look like, ['UA-27795084-5', 'mkdocs.org']
-        ('google_analytics', config_options.Deprecated(
+        'google_analytics': config_options.Deprecated(
             message=(
                 'The configuration option {} has been deprecated and '
                 'will be removed in a future release of MkDocs. See the '
                 'options available on your theme for an alternative.'
             ),
-            option_type=config_options.Type(list, length=2)
-        )),
-
+            option_type=config_options.Type(list, length=2),
+        ),
         # The address on which to serve the live reloading docs server.
-        ('dev_addr', config_options.IpAddress(default='127.0.0.1:8000')),
-
+        'dev_addr': config_options.IpAddress(default='127.0.0.1:8000'),
         # If `True`, use `<page_name>/index.hmtl` style files with hyperlinks to
         # the directory.If `False`, use `<page_name>.html style file with
         # hyperlinks to the file.
         # True generates nicer URLs, but False is useful if browsing the output on
         # a filesystem.
-        ('use_directory_urls', config_options.Type(bool, default=True)),
-
+        'use_directory_urls': config_options.Type(bool, default=True),
         # Specify a link to the project source repo to be included
         # in the documentation pages.
-        ('repo_url', config_options.RepoURL()),
-
+        'repo_url': config_options.RepoURL(),
         # A name to use for the link to the project source repo.
         # Default, If repo_url is unset then None, otherwise
         # "GitHub", "Bitbucket" or "GitLab" for known url or Hostname
         # for unknown urls.
-        ('repo_name', config_options.Type(str)),
-
+        'repo_name': config_options.Type(str),
         # Specify a URI to the docs dir in the project source repo, relative to the
         # repo_url. When set, a link directly to the page in the source repo will
         # be added to the generated HTML. If repo_url is not set also, this option
         # is ignored.
-        ('edit_uri', config_options.Type(str)),
-
+        'edit_uri': config_options.Type(str),
         # Specify which css or javascript files from the docs directory should be
         # additionally included in the site.
-        ('extra_css', config_options.Type(list, default=[])),
-        ('extra_javascript', config_options.Type(list, default=[])),
-
+        'extra_css': config_options.Type(list, default=[]),
+        'extra_javascript': config_options.Type(list, default=[]),
         # Similar to the above, but each template (HTML or XML) will be build with
         # Jinja2 and the global context.
-        ('extra_templates', config_options.Type(list, default=[])),
-
+        'extra_templates': config_options.Type(list, default=[]),
         # PyMarkdown extension names.
-        ('markdown_extensions', config_options.MarkdownExtensions(
-            builtins=['toc', 'tables', 'fenced_code'],
-            configkey='mdx_configs', default=[])),
-
+        'markdown_extensions': config_options.MarkdownExtensions(
+            builtins=['toc', 'tables', 'fenced_code'], configkey='mdx_configs', default=[]
+        ),
         # PyMarkdown Extension Configs. For internal use only.
-        ('mdx_configs', config_options.Private()),
-
+        'mdx_configs': config_options.Private(),
         # enabling strict mode causes MkDocs to stop the build when a problem is
         # encountered rather than display an error.
-        ('strict', config_options.Type(bool, default=False)),
-
+        'strict': config_options.Type(bool, default=False),
         # the remote branch to commit to when using gh-deploy
-        ('remote_branch', config_options.Type(
-            str, default='gh-pages')),
-
+        'remote_branch': config_options.Type(str, default='gh-pages'),
         # the remote name to push to when using gh-deploy
-        ('remote_name', config_options.Type(str, default='origin')),
-
+        'remote_name': config_options.Type(str, default='origin'),
         # extra is a mapping/dictionary of data that is passed to the template.
         # This allows template authors to require extra configuration that not
         # relevant to all themes and doesn't need to be explicitly supported by
         # MkDocs itself. A good example here would be including the current
         # project version.
-        ('extra', config_options.SubConfig()),
-
+        'extra': config_options.SubConfig(),
         # a list of plugins. Each item may contain a string name or a key value pair.
         # A key value pair should be the string name (as the key) and a dict of config
         # options (as the value).
-        ('plugins', config_options.Plugins(default=['search'])),
-
+        'plugins': config_options.Plugins(default=['search']),
         # a list of extra paths to watch while running `mkdocs serve`
-        ('watch', config_options.ListOfPaths(default=[]))
-    )
+        'watch': config_options.ListOfPaths(default=[]),
+    }
+    return tuple(schema.items())
diff --git a/mkdocs/contrib/search/__init__.py b/mkdocs/contrib/search/__init__.py
index 66eb92d8..a5549f8d 100644
--- a/mkdocs/contrib/search/__init__.py
+++ b/mkdocs/contrib/search/__init__.py
@@ -11,7 +11,7 @@ base_path = os.path.dirname(os.path.abspath(__file__))
 
 
 class LangOption(config_options.OptionallyRequired):
-    """ Validate Language(s) provided in config are known languages. """
+    """Validate Language(s) provided in config are known languages."""
 
     def get_lunr_supported_lang(self, lang):
         for lang_part in lang.split("_"):
@@ -40,14 +40,14 @@ class LangOption(config_options.OptionallyRequired):
 
 
 class SearchPlugin(BasePlugin):
-    """ Add a search feature to MkDocs. """
+    """Add a search feature to MkDocs."""
 
     config_scheme = (
         ('lang', LangOption()),
         ('separator', config_options.Type(str, default=r'[\s\-]+')),
         ('min_search_length', config_options.Type(int, default=3)),
         ('prebuild_index', config_options.Choice((False, True, 'node', 'python'), default=False)),
-        ('indexing', config_options.Choice(('full', 'sections', 'titles'), default='full'))
+        ('indexing', config_options.Choice(('full', 'sections', 'titles'), default='full')),
     )
 
     def on_config(self, config, **kwargs):
@@ -95,10 +95,10 @@ class SearchPlugin(BasePlugin):
                 files.append('lunr.stemmer.support.js')
             if len(self.config['lang']) > 1:
                 files.append('lunr.multi.js')
-            if ('ja' in self.config['lang'] or 'jp' in self.config['lang']):
+            if 'ja' in self.config['lang'] or 'jp' in self.config['lang']:
                 files.append('tinyseg.js')
             for lang in self.config['lang']:
-                if (lang != 'en'):
+                if lang != 'en':
                     files.append(f'lunr.{lang}.js')
 
             for filename in files:
diff --git a/mkdocs/contrib/search/search_index.py b/mkdocs/contrib/search/search_index.py
index bef81393..e610bb82 100644
--- a/mkdocs/contrib/search/search_index.py
+++ b/mkdocs/contrib/search/search_index.py
@@ -8,6 +8,7 @@ from html.parser import HTMLParser
 
 try:
     from lunr import lunr
+
     haslunrpy = True
 except ImportError:
     haslunrpy = False
@@ -44,11 +45,7 @@ class SearchIndex:
         text = text.replace('\u00a0', ' ')
         text = re.sub(r'[ \t\n\r\f\v]+', ' ', text.strip())
 
-        self._entries.append({
-            'title': title,
-            'text': text,
-            'location': loc
-        })
+        self._entries.append({'title': title, 'text': text, 'location': loc})
 
     def add_entry_from_context(self, page):
         """
@@ -70,11 +67,7 @@ class SearchIndex:
 
         # Create an entry for the full page.
         text = parser.stripped_html.rstrip('\n') if self.config['indexing'] == 'full' else ''
-        self._add_entry(
-            title=page.title,
-            text=text,
-            loc=url
-        )
+        self._add_entry(title=page.title, text=text, loc=url)
 
         if self.config['indexing'] in ['full', 'sections']:
             for section in parser.data:
@@ -91,28 +84,23 @@ class SearchIndex:
 
         text = ' '.join(section.text) if self.config['indexing'] == 'full' else ''
         if toc_item is not None:
-            self._add_entry(
-                title=toc_item.title,
-                text=text,
-                loc=abs_url + toc_item.url
-            )
+            self._add_entry(title=toc_item.title, text=text, loc=abs_url + toc_item.url)
 
     def generate_search_index(self):
         """python to json conversion"""
-        page_dicts = {
-            'docs': self._entries,
-            'config': self.config
-        }
+        page_dicts = {'docs': self._entries, 'config': self.config}
         data = json.dumps(page_dicts, sort_keys=True, separators=(',', ':'), default=str)
 
         if self.config['prebuild_index'] in (True, 'node'):
             try:
-                script_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'prebuild-index.js')
+                script_path = os.path.join(
+                    os.path.dirname(os.path.abspath(__file__)), 'prebuild-index.js'
+                )
                 p = subprocess.Popen(
                     ['node', script_path],
                     stdin=subprocess.PIPE,
                     stdout=subprocess.PIPE,
-                    stderr=subprocess.PIPE
+                    stderr=subprocess.PIPE,
                 )
                 idx, err = p.communicate(data.encode('utf-8'))
                 if not err:
@@ -127,8 +115,11 @@ class SearchIndex:
         elif self.config['prebuild_index'] == 'python':
             if haslunrpy:
                 idx = lunr(
-                    ref='location', fields=('title', 'text'), documents=self._entries,
-                    languages=self.config['lang'])
+                    ref='location',
+                    fields=('title', 'text'),
+                    documents=self._entries,
+                    languages=self.config['lang'],
+                )
                 page_dicts['index'] = idx.serialize()
                 data = json.dumps(page_dicts, sort_keys=True, separators=(',', ':'))
             else:
@@ -154,11 +145,7 @@ class ContentSection:
         self.title = title
 
     def __eq__(self, other):
-        return (
-            self.text == other.text and
-            self.id == other.id and
-            self.title == other.title
-        )
+        return self.text == other.text and self.id == other.id and self.title == other.title
 
 
 class ContentParser(HTMLParser):
diff --git a/mkdocs/exceptions.py b/mkdocs/exceptions.py
index c72175df..4ce39ba2 100644
--- a/mkdocs/exceptions.py
+++ b/mkdocs/exceptions.py
@@ -7,6 +7,7 @@ class MkDocsException(ClickException):
 
 class Abort(MkDocsException):
     """Abort the build"""
+
     def show(self, **kwargs):
         echo(self.format_message())
 
diff --git a/mkdocs/livereload/__init__.py b/mkdocs/livereload/__init__.py
index 9feb27f7..8f9b7bff 100644
--- a/mkdocs/livereload/__init__.py
+++ b/mkdocs/livereload/__init__.py
@@ -219,7 +219,7 @@ class LiveReloadServer(socketserver.ThreadingMixIn, wsgiref.simple_server.WSGISe
                     return [b"%d" % self._visible_epoch]
 
         if path.startswith(self.mount_path):
-            rel_file_path = path[len(self.mount_path):]
+            rel_file_path = path[len(self.mount_path) :]
 
             if path.endswith("/"):
                 rel_file_path += "index.html"
diff --git a/mkdocs/localization.py b/mkdocs/localization.py
index 6f772ec3..54a711df 100644
--- a/mkdocs/localization.py
+++ b/mkdocs/localization.py
@@ -7,9 +7,11 @@ from mkdocs.config.base import ValidationError
 try:
     from babel.core import Locale, UnknownLocaleError
     from babel.support import Translations, NullTranslations
+
     has_babel = True
 except ImportError:  # pragma: no cover
     from mkdocs.utils.babel_stub import Locale, UnknownLocaleError
+
     has_babel = False
 
 
diff --git a/mkdocs/plugins.py b/mkdocs/plugins.py
index 4cc978b9..4ea25ab6 100644
--- a/mkdocs/plugins.py
+++ b/mkdocs/plugins.py
@@ -15,14 +15,28 @@ log = logging.getLogger('mkdocs.plugins')
 
 
 EVENTS = (
-    'config', 'pre_build', 'files', 'nav', 'env', 'pre_template', 'template_context',
-    'post_template', 'pre_page', 'page_read_source', 'page_markdown',
-    'page_content', 'page_context', 'post_page', 'post_build', 'serve', 'build_error'
+    'config',
+    'pre_build',
+    'files',
+    'nav',
+    'env',
+    'pre_template',
+    'template_context',
+    'post_template',
+    'pre_page',
+    'page_read_source',
+    'page_markdown',
+    'page_content',
+    'page_context',
+    'post_page',
+    'post_build',
+    'serve',
+    'build_error',
 )
 
 
 def get_plugins():
-    """ Return a dict of all installed Plugins as {name: EntryPoint}. """
+    """Return a dict of all installed Plugins as {name: EntryPoint}."""
 
     plugins = importlib_metadata.entry_points(group='mkdocs.plugins')
 
@@ -48,7 +62,7 @@ class BasePlugin:
     config = {}
 
     def load_config(self, options, config_file_path=None):
-        """ Load config from a dict of options. Returns a tuple of (errors, warnings)."""
+        """Load config from a dict of options. Returns a tuple of (errors, warnings)."""
 
         self.config = Config(schema=self.config_scheme, config_file_path=config_file_path)
         self.config.load_dict(options)
@@ -70,7 +84,7 @@ class PluginCollection(OrderedDict):
         self.events = {x: [] for x in EVENTS}
 
     def _register_event(self, event_name, method):
-        """ Register a method for an event. """
+        """Register a method for an event."""
         self.events[event_name].append(method)
 
     def __setitem__(self, key, value, **kwargs):
@@ -78,7 +92,8 @@ class PluginCollection(OrderedDict):
             raise TypeError(
                 f'{self.__module__}.{self.__name__} only accepts values which'
                 f' are instances of {BasePlugin.__module__}.{BasePlugin.__name__}'
-                ' subclasses')
+                ' subclasses'
+            )
         super().__setitem__(key, value, **kwargs)
         # Register all of the event methods defined for this Plugin.
         for event_name in (x for x in dir(value) if x.startswith('on_')):
diff --git a/mkdocs/structure/files.py b/mkdocs/structure/files.py
index 4ab26988..39a68d80 100644
--- a/mkdocs/structure/files.py
+++ b/mkdocs/structure/files.py
@@ -10,7 +10,8 @@ log = logging.getLogger(__name__)
 
 
 class Files:
-    """ A collection of File objects. """
+    """A collection of File objects."""
+
     def __init__(self, files):
         self._files = files
 
@@ -28,45 +29,46 @@ class Files:
         return {file.src_path: file for file in self._files}
 
     def get_file_from_path(self, path):
-        """ Return a File instance with File.src_path equal to path. """
+        """Return a File instance with File.src_path equal to path."""
         return self.src_paths.get(os.path.normpath(path))
 
     def append(self, file):
-        """ Append file to Files collection. """
+        """Append file to Files collection."""
         self._files.append(file)
 
     def remove(self, file):
-        """ Remove file from Files collection. """
+        """Remove file from Files collection."""
         self._files.remove(file)
 
     def copy_static_files(self, dirty=False):
-        """ Copy static files from source to destination. """
+        """Copy static files from source to destination."""
         for file in self:
             if not file.is_documentation_page():
                 file.copy_file(dirty)
 
     def documentation_pages(self):
-        """ Return iterable of all Markdown page file objects. """
+        """Return iterable of all Markdown page file objects."""
         return [file for file in self if file.is_documentation_page()]
 
     def static_pages(self):
-        """ Return iterable of all static page file objects. """
+        """Return iterable of all static page file objects."""
         return [file for file in self if file.is_static_page()]
 
     def media_files(self):
-        """ Return iterable of all file objects which are not documentation or static pages. """
+        """Return iterable of all file objects which are not documentation or static pages."""
         return [file for file in self if file.is_media_file()]
 
     def javascript_files(self):
-        """ Return iterable of all javascript file objects. """
+        """Return iterable of all javascript file objects."""
         return [file for file in self if file.is_javascript()]
 
     def css_files(self):
-        """ Return iterable of all CSS file objects. """
+        """Return iterable of all CSS file objects."""
         return [file for file in self if file.is_css()]
 
     def add_files_from_theme(self, env, config):
-        """ Retrieve static files from Jinja environment and add to collection. """
+        """Retrieve static files from Jinja environment and add to collection."""
+
         def filter(name):
             # '.*' filters dot files/dirs at root level whereas '*/.*' filters nested levels
             patterns = ['.*', '*/.*', '*.py', '*.pyc', '*.html', '*readme*', 'mkdocs_theme.yml']
@@ -78,6 +80,7 @@ class Files:
                 if fnmatch.fnmatch(name.lower(), pattern):
                     return False
             return True
+
         for path in env.list_templates(filter_func=filter):
             # Theme files do not override docs_dir files
             path = os.path.normpath(path)
@@ -85,7 +88,9 @@ class Files:
                 for dir in config['theme'].dirs:
                     # Find the first theme dir which contains path
                     if os.path.isfile(os.path.join(dir, path)):
-                        self.append(File(path, dir, config['site_dir'], config['use_directory_urls']))
+                        self.append(
+                            File(path, dir, config['site_dir'], config['use_directory_urls'])
+                        )
                         break
 
 
@@ -121,6 +126,7 @@ class File:
     File.url
         The url of the destination file relative to the destination directory as a string.
     """
+
     def __init__(self, path, src_dir, dest_dir, use_directory_urls):
         self.page = None
         self.src_path = os.path.normpath(path)
@@ -132,10 +138,10 @@ class File:
 
     def __eq__(self, other):
         return (
-            isinstance(other, self.__class__) and
-            self.src_path == other.src_path and
-            self.abs_src_path == other.abs_src_path and
-            self.url == other.url
+            isinstance(other, self.__class__)
+            and self.src_path == other.src_path
+            and self.abs_src_path == other.abs_src_path
+            and self.url == other.url
         )
 
     def __repr__(self):
@@ -145,13 +151,13 @@ class File:
         )
 
     def _get_stem(self):
-        """ Return the name of the file without it's extension. """
+        """Return the name of the file without it's extension."""
         filename = os.path.basename(self.src_path)
         stem, ext = os.path.splitext(filename)
         return 'index' if stem in ('index', 'README') else stem
 
     def _get_dest_path(self, use_directory_urls):
-        """ Return destination path based on source path. """
+        """Return destination path based on source path."""
         if self.is_documentation_page():
             parent, filename = os.path.split(self.src_path)
             if not use_directory_urls or self.name == 'index':
@@ -164,7 +170,7 @@ class File:
         return self.src_path
 
     def _get_url(self, use_directory_urls):
-        """ Return url based in destination path. """
+        """Return url based in destination path."""
         url = self.dest_path.replace(os.path.sep, '/')
         dirname, filename = os.path.split(url)
         if use_directory_urls and filename == 'index.html':
@@ -175,11 +181,11 @@ class File:
         return urlquote(url)
 
     def url_relative_to(self, other):
-        """ Return url for file relative to other file. """
+        """Return url for file relative to other file."""
         return utils.get_relative_url(self.url, other.url if isinstance(other, File) else other)
 
     def copy_file(self, dirty=False):
-        """ Copy source file to destination, ensuring parent directories exist. """
+        """Copy source file to destination, ensuring parent directories exist."""
         if dirty and not self.is_modified():
             log.debug(f"Skip copying unmodified file: '{self.src_path}'")
         else:
@@ -192,28 +198,28 @@ class File:
         return True
 
     def is_documentation_page(self):
-        """ Return True if file is a Markdown page. """
+        """Return True if file is a Markdown page."""
         return utils.is_markdown_file(self.src_path)
 
     def is_static_page(self):
-        """ Return True if file is a static page (html, xml, json). """
+        """Return True if file is a static page (html, xml, json)."""
         return self.src_path.endswith(('.html', '.htm', '.xml', '.json'))
 
     def is_media_file(self):
-        """ Return True if file is not a documentation or static page. """
+        """Return True if file is not a documentation or static page."""
         return not (self.is_documentation_page() or self.is_static_page())
 
     def is_javascript(self):
-        """ Return True if file is a JavaScript file. """
+        """Return True if file is a JavaScript file."""
         return self.src_path.endswith(('.js', '.javascript'))
 
     def is_css(self):
-        """ Return True if file is a CSS file. """
+        """Return True if file is a CSS file."""
         return self.src_path.endswith('.css')
 
 
 def get_files(config):
-    """ Walk the `docs_dir` and return a Files collection. """
+    """Walk the `docs_dir` and return a Files collection."""
     files = []
     exclude = ['.*', '/templates']
 
@@ -234,15 +240,19 @@ def get_files(config):
                 continue
             # Skip README.md if an index file also exists in dir
             if filename == 'README.md' and 'index.md' in filenames:
-                log.warning(f"Both index.md and README.md found. Skipping README.md from {source_dir}")
+                log.warning(
+                    f"Both index.md and README.md found. Skipping README.md from {source_dir}"
+                )
                 continue
-            files.append(File(path, config['docs_dir'], config['site_dir'], config['use_directory_urls']))
+            files.append(
+                File(path, config['docs_dir'], config['site_dir'], config['use_directory_urls'])
+            )
 
     return Files(files)
 
 
 def _sort_files(filenames):
-    """ Always sort `index` or `README` as first filename in list. """
+    """Always sort `index` or `README` as first filename in list."""
 
     def key(f):
         if os.path.splitext(f)[0] in ['index', 'README']:
@@ -253,7 +263,7 @@ def _sort_files(filenames):
 
 
 def _filter_paths(basename, path, is_dir, exclude):
-    """ .gitignore style file filtering. """
+    """.gitignore style file filtering."""
     for item in exclude:
         # Items ending in '/' apply only to directories.
         if item.endswith('/') and not is_dir:
diff --git a/mkdocs/structure/nav.py b/mkdocs/structure/nav.py
index b8883773..e5433868 100644
--- a/mkdocs/structure/nav.py
+++ b/mkdocs/structure/nav.py
@@ -44,11 +44,11 @@ class Section:
         return f"Section(title='{self.title}')"
 
     def _get_active(self):
-        """ Return active status of section. """
+        """Return active status of section."""
         return self.__active
 
     def _set_active(self, value):
-        """ Set active status of section and ancestors. """
+        """Set active status of section and ancestors."""
         self.__active = bool(value)
         if self.parent is not None:
             self.parent.active = bool(value)
@@ -96,7 +96,7 @@ class Link:
 
 
 def get_navigation(files, config):
-    """ Build site navigation from config and files."""
+    """Build site navigation from config and files."""
     nav_config = config['nav'] or nest_paths(f.src_path for f in files.documentation_pages())
     items = _data_to_navigation(nav_config, files, config)
     if not isinstance(items, list):
@@ -114,7 +114,8 @@ def get_navigation(files, config):
         log.info(
             'The following pages exist in the docs directory, but are not '
             'included in the "nav" configuration:\n  - {}'.format(
-                '\n  - '.join([file.src_path for file in missing_from_config]))
+                '\n  - '.join([file.src_path for file in missing_from_config])
+            )
         )
         # Any documentation files not found in the nav should still have an associated page, so we
         # create them here. The Page object will automatically be assigned to `file.page` during
@@ -126,9 +127,7 @@ def get_navigation(files, config):
     for link in links:
         scheme, netloc, path, query, fragment = urlsplit(link.url)
         if scheme or netloc:
-            log.debug(
-                f"An external link to '{link.url}' is included in the 'nav' configuration."
-            )
+            log.debug(f"An external link to '{link.url}' is included in the 'nav' configuration.")
         elif link.url.startswith('/'):
             log.debug(
                 f"An absolute path to '{link.url}' is included in the 'nav' "
@@ -147,15 +146,15 @@ def _data_to_navigation(data, files, config):
     if isinstance(data, dict):
         return [
             _data_to_navigation((key, value), files, config)
-            if isinstance(value, str) else
-            Section(title=key, children=_data_to_navigation(value, files, config))
+            if isinstance(value, str)
+            else Section(title=key, children=_data_to_navigation(value, files, config))
             for key, value in data.items()
         ]
     elif isinstance(data, list):
         return [
             _data_to_navigation(item, files, config)[0]
-            if isinstance(item, dict) and len(item) == 1 else
-            _data_to_navigation(item, files, config)
+            if isinstance(item, dict) and len(item) == 1
+            else _data_to_navigation(item, files, config)
             for item in data
         ]
     title, path = data if isinstance(data, tuple) else (None, data)
diff --git a/mkdocs/structure/pages.py b/mkdocs/structure/pages.py
index db50ddb2..a1a68ae7 100644
--- a/mkdocs/structure/pages.py
+++ b/mkdocs/structure/pages.py
@@ -44,9 +44,9 @@ class Page:
 
     def __eq__(self, other):
         return (
-            isinstance(other, self.__class__) and
-            self.title == other.title and
-            self.file == other.file
+            isinstance(other, self.__class__)
+            and self.title == other.title
+            and self.file == other.file
         )
 
     def __repr__(self):
@@ -58,11 +58,11 @@ class Page:
         return '{}{}'.format('    ' * depth, repr(self))
 
     def _get_active(self):
-        """ Return active status of page. """
+        """Return active status of page."""
         return self.__active
 
     def _set_active(self, value):
-        """ Set active status of page and ancestors. """
+        """Set active status of page and ancestors."""
         self.__active = bool(value)
         if self.parent is not None:
             self.parent.active = bool(value)
@@ -112,9 +112,7 @@ class Page:
             self.edit_url = None
 
     def read_source(self, config):
-        source = config['plugins'].run_event(
-            'page_read_source', page=self, config=config
-        )
+        source = config['plugins'].run_event('page_read_source', page=self, config=config)
         if source is None:
             try:
                 with open(self.file.abs_src_path, encoding='utf-8-sig', errors='strict') as f:
@@ -164,13 +162,11 @@ class Page:
         Convert the Markdown source file to HTML as per the config.
         """
 
-        extensions = [
-            _RelativePathExtension(self.file, files)
-        ] + config['markdown_extensions']
+        extensions = [_RelativePathExtension(self.file, files)] + config['markdown_extensions']
 
         md = markdown.Markdown(
             extensions=extensions,
-            extension_configs=config['mdx_configs'] or {}
+            extension_configs=config['mdx_configs'] or {},
         )
         self.content = md.convert(self.markdown)
         self.toc = get_toc(getattr(md, 'toc_tokens', []))
@@ -205,8 +201,15 @@ class _RelativePathTreeprocessor(Treeprocessor):
     def path_to_url(self, url):
         scheme, netloc, path, query, fragment = urlsplit(url)
 
-        if (scheme or netloc or not path or url.startswith('/') or url.startswith('\\')
-                or AMP_SUBSTITUTE in url or '.' not in os.path.split(path)[-1]):
+        if (
+            scheme
+            or netloc
+            or not path
+            or url.startswith('/')
+            or url.startswith('\\')
+            or AMP_SUBSTITUTE in url
+            or '.' not in os.path.split(path)[-1]
+        ):
             # Ignore URLs unless they are a relative link to a source file.
             # AMP_SUBSTITUTE is used internally by Markdown only for email.
             # No '.' in the last part of a path indicates path does not point to a file.
diff --git a/mkdocs/structure/toc.py b/mkdocs/structure/toc.py
index 72250ffe..9541b036 100644
--- a/mkdocs/structure/toc.py
+++ b/mkdocs/structure/toc.py
@@ -19,6 +19,7 @@ class TableOfContents:
     """
     Represents the table of contents for a given page.
     """
+
     def __init__(self, items):
         self.items = items
 
@@ -36,6 +37,7 @@ class AnchorLink:
     """
     A single entry in the table of contents.
     """
+
     def __init__(self, title, id, level):
         self.title, self.id, self.level = title, id, level
         self.children = []
diff --git a/mkdocs/tests/babel_cmd_tests.py b/mkdocs/tests/babel_cmd_tests.py
index 1a47738a..59dfa6c8 100644
--- a/mkdocs/tests/babel_cmd_tests.py
+++ b/mkdocs/tests/babel_cmd_tests.py
@@ -9,14 +9,13 @@ BASE_DIR = path.normpath(path.join(path.abspath(path.dirname(__file__)), '../../
 
 
 class ThemeMixinTests(unittest.TestCase):
-
     def test_dict_entry_point(self):
         inst = babel.ThemeMixin()
         inst.distribution = Distribution()
         inst.distribution.entry_points = {
             'mkdocs.themes': [
-                'mkdocs = mkdocs.themes.mkdocs'
-            ]
+                'mkdocs = mkdocs.themes.mkdocs',
+            ],
         }
         inst.theme = 'mkdocs'
         self.assertEqual(inst.get_theme_dir(), path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs'))
@@ -36,8 +35,8 @@ class ThemeMixinTests(unittest.TestCase):
         inst.distribution = Distribution()
         inst.distribution.entry_points = {
             'mkdocs.themes': [
-                'mkdocs = mkdocs.themes.mkdocs'
-            ]
+                'mkdocs = mkdocs.themes.mkdocs',
+            ],
         }
         inst.theme = None
         self.assertEqual(inst.get_theme_dir(), path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs'))
@@ -49,10 +48,12 @@ class ThemeMixinTests(unittest.TestCase):
             'mkdocs.themes': [
                 'mkdocs = mkdocs.themes.mkdocs',
                 'readthedocs = mkdocs.themes.readthedocs',
-            ]
+            ],
         }
         inst.theme = 'readthedocs'
-        self.assertEqual(inst.get_theme_dir(), path.join(BASE_DIR, 'mkdocs', 'themes', 'readthedocs'))
+        self.assertEqual(
+            inst.get_theme_dir(), path.join(BASE_DIR, 'mkdocs', 'themes', 'readthedocs')
+        )
 
     def test_multiple_entry_points_no_default(self):
         inst = babel.ThemeMixin()
@@ -61,7 +62,7 @@ class ThemeMixinTests(unittest.TestCase):
             'mkdocs.themes': [
                 'mkdocs = mkdocs.themes.mkdocs',
                 'readthedocs = mkdocs.themes.readthedocs',
-            ]
+            ],
         }
         inst.theme = None
         self.assertRaises(DistutilsOptionError, inst.get_theme_dir)
@@ -78,15 +79,14 @@ class ThemeMixinTests(unittest.TestCase):
         inst.distribution = Distribution()
         inst.distribution.entry_points = {
             'mkdocs.themes': [
-                'mkdocs = mkdocs.themes.mkdocs'
-            ]
+                'mkdocs = mkdocs.themes.mkdocs',
+            ],
         }
         inst.theme = 'undefined'
         self.assertRaises(DistutilsOptionError, inst.get_theme_dir)
 
 
 class CommandTests(unittest.TestCase):
-
     def test_compile_catalog(self):
         dist = Distribution()
         dist.entry_points = '''
@@ -136,7 +136,9 @@ class CommandTests(unittest.TestCase):
         cmd.theme = 'mkdocs'
         cmd.finalize_options()
         self.assertEqual(cmd.input_paths, [path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs')])
-        self.assertEqual(cmd.output_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.output_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.mapping_file, babel.DEFAULT_MAPPING_FILE)
         self.assertEqual(cmd.project, 'foo')
         self.assertEqual(cmd.version, '1.2')
@@ -153,7 +155,9 @@ class CommandTests(unittest.TestCase):
         cmd.finalize_options()
         self.assertEqual(cmd.theme, 'mkdocs')
         self.assertEqual(cmd.input_paths, [path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs')])
-        self.assertEqual(cmd.output_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.output_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
 
     def test_extract_messages_ingore_theme(self):
         dist = Distribution(dict(name='foo', version='1.2'))
@@ -182,7 +186,9 @@ class CommandTests(unittest.TestCase):
         cmd.input_paths = 'mkdocs/tests'
         cmd.finalize_options()
         self.assertEqual(cmd.input_paths, ['mkdocs/tests'])
-        self.assertEqual(cmd.output_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.output_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
 
     def test_extract_messages_ingore_theme_for_output(self):
         dist = Distribution(dict(name='foo', version='1.2'))
@@ -209,7 +215,9 @@ class CommandTests(unittest.TestCase):
         cmd.theme = 'mkdocs'
         cmd.locale = 'en'
         cmd.finalize_options()
-        self.assertEqual(cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.output_dir, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/locales'))
 
     def test_init_catalog_default_theme(self):
@@ -224,7 +232,9 @@ class CommandTests(unittest.TestCase):
         self.assertIsNone(cmd.theme)
         cmd.finalize_options()
         self.assertEqual(cmd.theme, 'mkdocs')
-        self.assertEqual(cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.output_dir, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/locales'))
 
     def test_init_catalog_ignore_theme(self):
@@ -270,7 +280,9 @@ class CommandTests(unittest.TestCase):
         cmd.locale = 'en'
         cmd.output_dir = 'foo/bar'
         cmd.finalize_options()
-        self.assertEqual(cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.output_dir, 'foo/bar')
 
     def test_update_catalog(self):
@@ -283,7 +295,9 @@ class CommandTests(unittest.TestCase):
         cmd.initialize_options()
         cmd.theme = 'mkdocs'
         cmd.finalize_options()
-        self.assertEqual(cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.output_dir, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/locales'))
 
     def test_update_catalog_default_theme(self):
@@ -298,7 +312,9 @@ class CommandTests(unittest.TestCase):
         self.assertIsNone(cmd.theme)
         cmd.finalize_options()
         self.assertEqual(cmd.theme, 'mkdocs')
-        self.assertEqual(cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.output_dir, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/locales'))
 
     def test_update_catalog_ignore_theme(self):
@@ -344,5 +360,7 @@ class CommandTests(unittest.TestCase):
         cmd.locale = 'en'
         cmd.output_dir = 'foo/bar'
         cmd.finalize_options()
-        self.assertEqual(cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot'))
+        self.assertEqual(
+            cmd.input_file, path.join(BASE_DIR, 'mkdocs', 'themes', 'mkdocs/messages.pot')
+        )
         self.assertEqual(cmd.output_dir, 'foo/bar')
diff --git a/mkdocs/tests/base.py b/mkdocs/tests/base.py
index 1270db3a..3fbb4943 100644
--- a/mkdocs/tests/base.py
+++ b/mkdocs/tests/base.py
@@ -14,17 +14,15 @@ def dedent(text):
 
 
 def get_markdown_toc(markdown_source):
-    """ Return TOC generated by Markdown parser from Markdown source text. """
+    """Return TOC generated by Markdown parser from Markdown source text."""
     md = markdown.Markdown(extensions=['toc'])
     md.convert(markdown_source)
     return md.toc_tokens
 
 
 def load_config(**cfg):
-    """ Helper to build a simple config for testing. """
-    path_base = os.path.join(
-        os.path.abspath(os.path.dirname(__file__)), 'integration', 'minimal'
-    )
+    """Helper to build a simple config for testing."""
+    path_base = os.path.join(os.path.abspath(os.path.dirname(__file__)), 'integration', 'minimal')
     cfg = cfg or {}
     if 'site_name' not in cfg:
         cfg['site_name'] = 'Example'
@@ -33,7 +31,9 @@ def load_config(**cfg):
     if 'docs_dir' not in cfg:
         # Point to an actual dir to avoid a 'does not exist' error on validation.
         cfg['docs_dir'] = os.path.join(path_base, 'docs')
-    conf = config.Config(schema=config_defaults.get_schema(), config_file_path=cfg['config_file_path'])
+    conf = config.Config(
+        schema=config_defaults.get_schema(), config_file_path=cfg['config_file_path']
+    )
     conf.load_dict(cfg)
 
     errors_warnings = conf.validate()
@@ -78,7 +78,9 @@ def tempdir(files=None, **kw):
                     pth = os.path.join(td, path)
                     utils.write_file(content.encode(encoding='utf-8'), pth)
                 return fn(self, td, *args)
+
         return wrapper
+
     return decorator
 
 
diff --git a/mkdocs/tests/build_tests.py b/mkdocs/tests/build_tests.py
index 266309d5..c99c7e44 100644
--- a/mkdocs/tests/build_tests.py
+++ b/mkdocs/tests/build_tests.py
@@ -13,9 +13,11 @@ from mkdocs.utils import meta
 
 
 def build_page(title, path, config, md_src=''):
-    """ Helper which returns a Page object. """
+    """Helper which returns a Page object."""
 
-    files = Files([File(path, config['docs_dir'], config['site_dir'], config['use_directory_urls'])])
+    files = Files(
+        [File(path, config['docs_dir'], config['site_dir'], config['use_directory_urls'])]
+    )
     page = Page(title, list(files)[0], config)
     # Fake page.read_source()
     page.markdown, page.meta = meta.get_data(md_src)
@@ -23,7 +25,6 @@ def build_page(title, path, config, md_src=''):
 
 
 class BuildTests(PathAssertionMixin, unittest.TestCase):
-
     def _get_env_with_null_translations(self, config):
         env = config['theme'].get_env()
         env.add_extension('jinja2.ext.i18n')
@@ -34,24 +35,26 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
 
     def test_context_base_url_homepage(self):
         nav_cfg = [
-            {'Home': 'index.md'}
+            {'Home': 'index.md'},
         ]
         cfg = load_config(nav=nav_cfg, use_directory_urls=False)
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[0])
         self.assertEqual(context['base_url'], '.')
 
     def test_context_base_url_homepage_use_directory_urls(self):
         nav_cfg = [
-            {'Home': 'index.md'}
+            {'Home': 'index.md'},
         ]
         cfg = load_config(nav=nav_cfg)
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[0])
         self.assertEqual(context['base_url'], '.')
@@ -59,13 +62,14 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     def test_context_base_url_nested_page(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'Nested': 'foo/bar.md'}
+            {'Nested': 'foo/bar.md'},
         ]
         cfg = load_config(nav=nav_cfg, use_directory_urls=False)
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[1])
         self.assertEqual(context['base_url'], '..')
@@ -73,13 +77,14 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     def test_context_base_url_nested_page_use_directory_urls(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'Nested': 'foo/bar.md'}
+            {'Nested': 'foo/bar.md'},
         ]
         cfg = load_config(nav=nav_cfg)
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[1])
         self.assertEqual(context['base_url'], '../..')
@@ -116,17 +121,18 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
 
     def test_context_extra_css_js_from_homepage(self):
         nav_cfg = [
-            {'Home': 'index.md'}
+            {'Home': 'index.md'},
         ]
         cfg = load_config(
             nav=nav_cfg,
             extra_css=['style.css'],
             extra_javascript=['script.js'],
-            use_directory_urls=False
+            use_directory_urls=False,
         )
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[0])
         self.assertEqual(context['extra_css'], ['style.css'])
@@ -135,18 +141,19 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     def test_context_extra_css_js_from_nested_page(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'Nested': 'foo/bar.md'}
+            {'Nested': 'foo/bar.md'},
         ]
         cfg = load_config(
             nav=nav_cfg,
             extra_css=['style.css'],
             extra_javascript=['script.js'],
-            use_directory_urls=False
+            use_directory_urls=False,
         )
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[1])
         self.assertEqual(context['extra_css'], ['../style.css'])
@@ -155,17 +162,18 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     def test_context_extra_css_js_from_nested_page_use_directory_urls(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'Nested': 'foo/bar.md'}
+            {'Nested': 'foo/bar.md'},
         ]
         cfg = load_config(
             nav=nav_cfg,
             extra_css=['style.css'],
-            extra_javascript=['script.js']
+            extra_javascript=['script.js'],
         )
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         context = build.get_context(nav, files, cfg, nav.pages[1])
         self.assertEqual(context['extra_css'], ['../../style.css'])
@@ -213,7 +221,9 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
             build._build_theme_template('missing.html', env, mock.Mock(), cfg, mock.Mock())
         self.assertEqual(
             cm.output,
-            ["WARNING:mkdocs.commands.build:Template skipped: 'missing.html' not found in theme directories."]
+            [
+                "WARNING:mkdocs.commands.build:Template skipped: 'missing.html' not found in theme directories."
+            ],
         )
         mock_write_file.assert_not_called()
         mock_build_template.assert_not_called()
@@ -227,7 +237,7 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
             build._build_theme_template('main.html', env, mock.Mock(), cfg, mock.Mock())
         self.assertEqual(
             cm.output,
-            ["INFO:mkdocs.commands.build:Template skipped: 'main.html' generated empty output."]
+            ["INFO:mkdocs.commands.build:Template skipped: 'main.html' generated empty output."],
         )
         mock_write_file.assert_not_called()
         mock_build_template.assert_called_once()
@@ -237,48 +247,54 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     @mock.patch('mkdocs.commands.build.open', mock.mock_open(read_data='template content'))
     def test_build_extra_template(self):
         cfg = load_config()
-        files = Files([
+        fs = [
             File('foo.html', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         build._build_extra_template('foo.html', files, cfg, mock.Mock())
 
     @mock.patch('mkdocs.commands.build.open', mock.mock_open(read_data='template content'))
     def test_skip_missing_extra_template(self):
         cfg = load_config()
-        files = Files([
+        fs = [
             File('foo.html', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         with self.assertLogs('mkdocs', level='INFO') as cm:
             build._build_extra_template('missing.html', files, cfg, mock.Mock())
         self.assertEqual(
             cm.output,
-            ["WARNING:mkdocs.commands.build:Template skipped: 'missing.html' not found in docs_dir."]
+            [
+                "WARNING:mkdocs.commands.build:Template skipped: 'missing.html' not found in docs_dir."
+            ],
         )
 
     @mock.patch('mkdocs.commands.build.open', side_effect=OSError('Error message.'))
     def test_skip_ioerror_extra_template(self, mock_open):
         cfg = load_config()
-        files = Files([
+        fs = [
             File('foo.html', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         with self.assertLogs('mkdocs', level='INFO') as cm:
             build._build_extra_template('foo.html', files, cfg, mock.Mock())
         self.assertEqual(
             cm.output,
-            ["WARNING:mkdocs.commands.build:Error reading template 'foo.html': Error message."]
+            ["WARNING:mkdocs.commands.build:Error reading template 'foo.html': Error message."],
         )
 
     @mock.patch('mkdocs.commands.build.open', mock.mock_open(read_data=''))
     def test_skip_extra_template_empty_output(self):
         cfg = load_config()
-        files = Files([
+        fs = [
             File('foo.html', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        ]
+        files = Files(fs)
         with self.assertLogs('mkdocs', level='INFO') as cm:
             build._build_extra_template('foo.html', files, cfg, mock.Mock())
         self.assertEqual(
             cm.output,
-            ["INFO:mkdocs.commands.build:Template skipped: 'foo.html' generated empty output."]
+            ["INFO:mkdocs.commands.build:Template skipped: 'foo.html' generated empty output."],
         )
 
     # Test build._populate_page
@@ -298,7 +314,9 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
         page = Page('Foo', file, cfg)
         build._populate_page(page, cfg, Files([file]), dirty=True)
         self.assertTrue(page.markdown.startswith('# Welcome to MkDocs'))
-        self.assertTrue(page.content.startswith('<h1 id="welcome-to-mkdocs">Welcome to MkDocs</h1>'))
+        self.assertTrue(
+            page.content.startswith('<h1 id="welcome-to-mkdocs">Welcome to MkDocs</h1>')
+        )
 
     @tempdir(files={'index.md': 'page content'})
     @tempdir(files={'index.html': '<p>page content</p>'})
@@ -321,15 +339,18 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
             with self.assertRaises(OSError):
                 build._populate_page(page, cfg, Files([file]))
         self.assertEqual(
-            cm.output, [
+            cm.output,
+            [
                 'ERROR:mkdocs.structure.pages:File not found: missing.md',
-                "ERROR:mkdocs.commands.build:Error reading page 'missing.md': Error message."
-            ]
+                "ERROR:mkdocs.commands.build:Error reading page 'missing.md': Error message.",
+            ],
         )
         mock_open.assert_called_once()
 
     @tempdir(files={'index.md': 'page content'})
-    @mock.patch('mkdocs.plugins.PluginCollection.run_event', side_effect=PluginError('Error message.'))
+    @mock.patch(
+        'mkdocs.plugins.PluginCollection.run_event', side_effect=PluginError('Error message.')
+    )
     def test_populate_page_read_plugin_error(self, docs_dir, mock_open):
         cfg = load_config(docs_dir=docs_dir)
         file = File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
@@ -338,9 +359,8 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
             with self.assertRaises(PluginError):
                 build._populate_page(page, cfg, Files([file]))
         self.assertEqual(
-            cm.output, [
-                "ERROR:mkdocs.commands.build:Error reading page 'index.md':"
-            ]
+            cm.output,
+            ["ERROR:mkdocs.commands.build:Error reading page 'index.md':"],
         )
         mock_open.assert_called_once()
 
@@ -349,7 +369,8 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     @tempdir()
     def test_build_page(self, site_dir):
         cfg = load_config(site_dir=site_dir, nav=['index.md'], plugins=[])
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         page = files.documentation_pages()[0].page
         # Fake populate page
@@ -363,13 +384,16 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     @mock.patch('jinja2.environment.Template.render', return_value='')
     def test_build_page_empty(self, site_dir, render_mock):
         cfg = load_config(site_dir=site_dir, nav=['index.md'], plugins=[])
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         with self.assertLogs('mkdocs', level='INFO') as cm:
-            build._build_page(files.documentation_pages()[0].page, cfg, files, nav, cfg['theme'].get_env())
+            build._build_page(
+                files.documentation_pages()[0].page, cfg, files, nav, cfg['theme'].get_env()
+            )
         self.assertEqual(
             cm.output,
-            ["INFO:mkdocs.commands.build:Page skipped: 'index.md'. Generated empty output."]
+            ["INFO:mkdocs.commands.build:Page skipped: 'index.md'. Generated empty output."],
         )
         self.assertPathNotFile(site_dir, 'index.html')
         render_mock.assert_called_once()
@@ -379,34 +403,41 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     @mock.patch('mkdocs.utils.write_file')
     def test_build_page_dirty_modified(self, site_dir, docs_dir, mock_write_file):
         cfg = load_config(docs_dir=docs_dir, site_dir=site_dir, nav=['index.md'], plugins=[])
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         page = files.documentation_pages()[0].page
         # Fake populate page
         page.title = 'Title'
         page.markdown = 'new page content'
         page.content = '<p>new page content</p>'
-        build._build_page(page, cfg, files, nav, self._get_env_with_null_translations(cfg), dirty=True)
+        build._build_page(
+            page, cfg, files, nav, self._get_env_with_null_translations(cfg), dirty=True
+        )
         mock_write_file.assert_not_called()
 
     @tempdir(files={'testing.html': '<p>page content</p>'})
     @mock.patch('mkdocs.utils.write_file')
     def test_build_page_dirty_not_modified(self, site_dir, mock_write_file):
         cfg = load_config(site_dir=site_dir, nav=['testing.md'], plugins=[])
-        files = Files([File('testing.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('testing.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         page = files.documentation_pages()[0].page
         # Fake populate page
         page.title = 'Title'
         page.markdown = 'page content'
         page.content = '<p>page content</p>'
-        build._build_page(page, cfg, files, nav, self._get_env_with_null_translations(cfg), dirty=True)
+        build._build_page(
+            page, cfg, files, nav, self._get_env_with_null_translations(cfg), dirty=True
+        )
         mock_write_file.assert_called_once()
 
     @tempdir()
     def test_build_page_custom_template(self, site_dir):
         cfg = load_config(site_dir=site_dir, nav=['index.md'], plugins=[])
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         page = files.documentation_pages()[0].page
         # Fake populate page
@@ -421,7 +452,8 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
     @mock.patch('mkdocs.utils.write_file', side_effect=OSError('Error message.'))
     def test_build_page_error(self, site_dir, mock_write_file):
         cfg = load_config(site_dir=site_dir, nav=['index.md'], plugins=[])
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         page = files.documentation_pages()[0].page
         # Fake populate page
@@ -430,24 +462,21 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
         page.content = '<p>page content</p>'
         with self.assertLogs('mkdocs', level='ERROR') as cm:
             with self.assertRaises(OSError):
-                build._build_page(
-                    page,
-                    cfg,
-                    files,
-                    nav,
-                    self._get_env_with_null_translations(cfg)
-                )
+                build._build_page(page, cfg, files, nav, self._get_env_with_null_translations(cfg))
         self.assertEqual(
             cm.output,
-            ["ERROR:mkdocs.commands.build:Error building page 'index.md': Error message."]
+            ["ERROR:mkdocs.commands.build:Error building page 'index.md': Error message."],
         )
         mock_write_file.assert_called_once()
 
     @tempdir()
-    @mock.patch('mkdocs.plugins.PluginCollection.run_event', side_effect=PluginError('Error message.'))
+    @mock.patch(
+        'mkdocs.plugins.PluginCollection.run_event', side_effect=PluginError('Error message.')
+    )
     def test_build_page_plugin_error(self, site_dir, mock_write_file):
         cfg = load_config(site_dir=site_dir, nav=['index.md'], plugins=[])
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         nav = get_navigation(files, cfg)
         page = files.documentation_pages()[0].page
         # Fake populate page
@@ -459,20 +488,22 @@ class BuildTests(PathAssertionMixin, unittest.TestCase):
                 build._build_page(page, cfg, files, nav, cfg['theme'].get_env())
         self.assertEqual(
             cm.output,
-            ["ERROR:mkdocs.commands.build:Error building page 'index.md':"]
+            ["ERROR:mkdocs.commands.build:Error building page 'index.md':"],
         )
         mock_write_file.assert_called_once()
 
     # Test build.build
 
-    @tempdir(files={
-        'index.md': 'page content',
-        'empty.md': '',
-        'img.jpg': '',
-        'static.html': 'content',
-        '.hidden': 'content',
-        '.git/hidden': 'content'
-    })
+    @tempdir(
+        files={
+            'index.md': 'page content',
+            'empty.md': '',
+            'img.jpg': '',
+            'static.html': 'content',
+            '.hidden': 'content',
+            '.git/hidden': 'content',
+        }
+    )
     @tempdir()
     def test_copying_media(self, site_dir, docs_dir):
         cfg = load_config(docs_dir=docs_dir, site_dir=site_dir)
diff --git a/mkdocs/tests/cli_tests.py b/mkdocs/tests/cli_tests.py
index 40397d72..b84f127c 100644
--- a/mkdocs/tests/cli_tests.py
+++ b/mkdocs/tests/cli_tests.py
@@ -11,15 +11,13 @@ from mkdocs import __main__ as cli
 
 
 class CLITests(unittest.TestCase):
-
     def setUp(self):
         self.runner = CliRunner()
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_default(self, mock_serve):
 
-        result = self.runner.invoke(
-            cli.cli, ["serve"], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["serve"], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -30,14 +28,15 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_config_file(self, mock_serve):
 
         result = self.runner.invoke(
-            cli.cli, ["serve", "--config-file", "mkdocs.yml"], catch_exceptions=False)
+            cli.cli, ["serve", "--config-file", "mkdocs.yml"], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_serve.call_count, 1)
@@ -50,7 +49,8 @@ class CLITests(unittest.TestCase):
     def test_serve_dev_addr(self, mock_serve):
 
         result = self.runner.invoke(
-            cli.cli, ["serve", '--dev-addr', '0.0.0.0:80'], catch_exceptions=False)
+            cli.cli, ["serve", '--dev-addr', '0.0.0.0:80'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -61,14 +61,13 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_strict(self, mock_serve):
 
-        result = self.runner.invoke(
-            cli.cli, ["serve", '--strict'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["serve", '--strict'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -79,14 +78,15 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_theme(self, mock_serve):
 
         result = self.runner.invoke(
-            cli.cli, ["serve", '--theme', 'readthedocs'], catch_exceptions=False)
+            cli.cli, ["serve", '--theme', 'readthedocs'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -97,14 +97,15 @@ class CLITests(unittest.TestCase):
             theme='readthedocs',
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_use_directory_urls(self, mock_serve):
 
         result = self.runner.invoke(
-            cli.cli, ["serve", '--use-directory-urls'], catch_exceptions=False)
+            cli.cli, ["serve", '--use-directory-urls'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -115,14 +116,15 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=True,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_no_directory_urls(self, mock_serve):
 
         result = self.runner.invoke(
-            cli.cli, ["serve", '--no-directory-urls'], catch_exceptions=False)
+            cli.cli, ["serve", '--no-directory-urls'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -133,14 +135,13 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=False,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_livereload(self, mock_serve):
 
-        result = self.runner.invoke(
-            cli.cli, ["serve", '--livereload'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["serve", '--livereload'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -151,14 +152,13 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_no_livereload(self, mock_serve):
 
-        result = self.runner.invoke(
-            cli.cli, ["serve", '--no-livereload'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["serve", '--no-livereload'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -169,14 +169,13 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_dirtyreload(self, mock_serve):
 
-        result = self.runner.invoke(
-            cli.cli, ["serve", '--dirtyreload'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["serve", '--dirtyreload'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -187,14 +186,13 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=False,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.commands.serve.serve', autospec=True)
     def test_serve_watch_theme(self, mock_serve):
 
-        result = self.runner.invoke(
-            cli.cli, ["serve", '--watch-theme'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["serve", '--watch-theme'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_serve.assert_called_once_with(
@@ -205,15 +203,14 @@ class CLITests(unittest.TestCase):
             theme=None,
             use_directory_urls=None,
             watch_theme=True,
-            watch=()
+            watch=(),
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
     @mock.patch('mkdocs.commands.build.build', autospec=True)
     def test_build_defaults(self, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['build'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['build'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -225,7 +222,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
         handler = logging._handlers.get('MkDocsStreamHandler')
         self.assertEqual(handler.level, logging.INFO)
@@ -234,8 +231,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.build.build', autospec=True)
     def test_build_clean(self, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['build', '--clean'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['build', '--clean'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -247,8 +243,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.build.build', autospec=True)
     def test_build_dirty(self, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['build', '--dirty'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['build', '--dirty'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -261,7 +256,8 @@ class CLITests(unittest.TestCase):
     def test_build_config_file(self, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['build', '--config-file', 'mkdocs.yml'], catch_exceptions=False)
+            cli.cli, ['build', '--config-file', 'mkdocs.yml'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -275,8 +271,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.build.build', autospec=True)
     def test_build_strict(self, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['build', '--strict'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['build', '--strict'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -285,7 +280,7 @@ class CLITests(unittest.TestCase):
             strict=True,
             theme=None,
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -293,7 +288,8 @@ class CLITests(unittest.TestCase):
     def test_build_theme(self, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['build', '--theme', 'readthedocs'], catch_exceptions=False)
+            cli.cli, ['build', '--theme', 'readthedocs'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -302,7 +298,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme='readthedocs',
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -310,7 +306,8 @@ class CLITests(unittest.TestCase):
     def test_build_use_directory_urls(self, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['build', '--use-directory-urls'], catch_exceptions=False)
+            cli.cli, ['build', '--use-directory-urls'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -319,7 +316,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=True,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -327,7 +324,8 @@ class CLITests(unittest.TestCase):
     def test_build_no_directory_urls(self, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['build', '--no-directory-urls'], catch_exceptions=False)
+            cli.cli, ['build', '--no-directory-urls'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -336,7 +334,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=False,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -344,7 +342,8 @@ class CLITests(unittest.TestCase):
     def test_build_site_dir(self, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['build', '--site-dir', 'custom'], catch_exceptions=False)
+            cli.cli, ['build', '--site-dir', 'custom'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -360,8 +359,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.build.build', autospec=True)
     def test_build_verbose(self, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['build', '--verbose'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['build', '--verbose'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -372,8 +370,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.build.build', autospec=True)
     def test_build_quiet(self, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['build', '--quiet'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['build', '--quiet'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_build.call_count, 1)
@@ -383,8 +380,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.new.new', autospec=True)
     def test_new(self, mock_new):
 
-        result = self.runner.invoke(
-            cli.cli, ["new", "project"], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ["new", "project"], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         mock_new.assert_called_once_with('project')
@@ -394,8 +390,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy.gh_deploy', autospec=True)
     def test_gh_deploy_defaults(self, mock_gh_deploy, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['gh-deploy'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['gh-deploy'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -417,7 +412,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -425,8 +420,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy.gh_deploy', autospec=True)
     def test_gh_deploy_clean(self, mock_gh_deploy, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--clean'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['gh-deploy', '--clean'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -440,8 +434,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy.gh_deploy', autospec=True)
     def test_gh_deploy_dirty(self, mock_gh_deploy, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--dirty'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['gh-deploy', '--dirty'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -456,7 +449,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_config_file(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--config-file', 'mkdocs.yml'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--config-file', 'mkdocs.yml'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -473,7 +467,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_message(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--message', 'A commit message'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--message', 'A commit message'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -489,7 +484,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_remote_branch(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--remote-branch', 'foo'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--remote-branch', 'foo'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -501,7 +497,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -510,7 +506,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_remote_name(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--remote-name', 'foo'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--remote-name', 'foo'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -522,7 +519,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -530,8 +527,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy.gh_deploy', autospec=True)
     def test_gh_deploy_force(self, mock_gh_deploy, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--force'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['gh-deploy', '--force'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -547,7 +543,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_ignore_version(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--ignore-version'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--ignore-version'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -562,8 +559,7 @@ class CLITests(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy.gh_deploy', autospec=True)
     def test_gh_deploy_strict(self, mock_gh_deploy, mock_build, mock_load_config):
 
-        result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--strict'], catch_exceptions=False)
+        result = self.runner.invoke(cli.cli, ['gh-deploy', '--strict'], catch_exceptions=False)
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -575,7 +571,7 @@ class CLITests(unittest.TestCase):
             strict=True,
             theme=None,
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -584,7 +580,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_theme(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--theme', 'readthedocs'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--theme', 'readthedocs'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -596,7 +593,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme='readthedocs',
             use_directory_urls=None,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -605,7 +602,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_use_directory_urls(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--use-directory-urls'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--use-directory-urls'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -617,7 +615,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=True,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -626,7 +624,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_no_directory_urls(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--no-directory-urls'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--no-directory-urls'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -638,7 +637,7 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=False,
-            site_dir=None
+            site_dir=None,
         )
 
     @mock.patch('mkdocs.config.load_config', autospec=True)
@@ -647,7 +646,8 @@ class CLITests(unittest.TestCase):
     def test_gh_deploy_site_dir(self, mock_gh_deploy, mock_build, mock_load_config):
 
         result = self.runner.invoke(
-            cli.cli, ['gh-deploy', '--site-dir', 'custom'], catch_exceptions=False)
+            cli.cli, ['gh-deploy', '--site-dir', 'custom'], catch_exceptions=False
+        )
 
         self.assertEqual(result.exit_code, 0)
         self.assertEqual(mock_gh_deploy.call_count, 1)
@@ -659,5 +659,5 @@ class CLITests(unittest.TestCase):
             strict=None,
             theme=None,
             use_directory_urls=None,
-            site_dir='custom'
+            site_dir='custom',
         )
diff --git a/mkdocs/tests/config/base_tests.py b/mkdocs/tests/config/base_tests.py
index 0f1f8d54..b9a37822 100644
--- a/mkdocs/tests/config/base_tests.py
+++ b/mkdocs/tests/config/base_tests.py
@@ -9,20 +9,26 @@ from mkdocs.config.config_options import BaseConfigOption
 
 
 class ConfigBaseTests(unittest.TestCase):
-
     def test_unrecognised_keys(self):
 
         c = base.Config(schema=defaults.get_schema())
-        c.load_dict({
-            'not_a_valid_config_option': "test"
-        })
+        c.load_dict(
+            {
+                'not_a_valid_config_option': "test",
+            }
+        )
 
         failed, warnings = c.validate()
 
-        self.assertEqual(warnings, [
-            ('not_a_valid_config_option',
-                'Unrecognised configuration name: not_a_valid_config_option')
-        ])
+        self.assertEqual(
+            warnings,
+            [
+                (
+                    'not_a_valid_config_option',
+                    'Unrecognised configuration name: not_a_valid_config_option',
+                )
+            ],
+        )
 
     def test_missing_required(self):
 
@@ -197,8 +203,7 @@ class ConfigBaseTests(unittest.TestCase):
 
         config_file = tempfile.NamedTemporaryFile('w', delete=False)
         try:
-            config_file.write(
-                "site_dir: output\nsite_uri: https://www.mkdocs.org\n")
+            config_file.write("site_dir: output\nsite_uri: https://www.mkdocs.org\n")
             config_file.flush()
             config_file.close()
 
@@ -212,7 +217,7 @@ class ConfigBaseTests(unittest.TestCase):
             def pre_validation(self, config, key_name):
                 raise base.ValidationError('pre_validation error')
 
-        c = base.Config(schema=(('invalid_option', InvalidConfigOption()), ))
+        c = base.Config(schema=(('invalid_option', InvalidConfigOption()),))
 
         errors, warnings = c.validate()
 
@@ -227,7 +232,7 @@ class ConfigBaseTests(unittest.TestCase):
             def run_validation(self, value):
                 raise base.ValidationError('run_validation error')
 
-        c = base.Config(schema=(('invalid_option', InvalidConfigOption()), ))
+        c = base.Config(schema=(('invalid_option', InvalidConfigOption()),))
 
         errors, warnings = c.validate()
 
@@ -242,7 +247,7 @@ class ConfigBaseTests(unittest.TestCase):
             def post_validation(self, config, key_name):
                 raise base.ValidationError('post_validation error')
 
-        c = base.Config(schema=(('invalid_option', InvalidConfigOption()), ))
+        c = base.Config(schema=(('invalid_option', InvalidConfigOption()),))
 
         errors, warnings = c.validate()
 
@@ -253,7 +258,8 @@ class ConfigBaseTests(unittest.TestCase):
         self.assertEqual(len(warnings), 0)
 
     def test_pre_and_run_validation_errors(self):
-        """ A pre_validation error does not stop run_validation from running. """
+        """A pre_validation error does not stop run_validation from running."""
+
         class InvalidConfigOption(BaseConfigOption):
             def pre_validation(self, config, key_name):
                 raise base.ValidationError('pre_validation error')
@@ -261,7 +267,7 @@ class ConfigBaseTests(unittest.TestCase):
             def run_validation(self, value):
                 raise base.ValidationError('run_validation error')
 
-        c = base.Config(schema=(('invalid_option', InvalidConfigOption()), ))
+        c = base.Config(schema=(('invalid_option', InvalidConfigOption()),))
 
         errors, warnings = c.validate()
 
@@ -275,7 +281,8 @@ class ConfigBaseTests(unittest.TestCase):
         self.assertEqual(len(warnings), 0)
 
     def test_run_and_post_validation_errors(self):
-        """ A run_validation error stops post_validation from running. """
+        """A run_validation error stops post_validation from running."""
+
         class InvalidConfigOption(BaseConfigOption):
             def run_validation(self, value):
                 raise base.ValidationError('run_validation error')
@@ -283,7 +290,7 @@ class ConfigBaseTests(unittest.TestCase):
             def post_validation(self, config, key_name):
                 raise base.ValidationError('post_validation error')
 
-        c = base.Config(schema=(('invalid_option', InvalidConfigOption()), ))
+        c = base.Config(schema=(('invalid_option', InvalidConfigOption()),))
 
         errors, warnings = c.validate()
 
@@ -304,16 +311,19 @@ class ConfigBaseTests(unittest.TestCase):
             def post_validation(self, config, key_name):
                 self.warnings.append('post_validation warning')
 
-        c = base.Config(schema=(('invalid_option', InvalidConfigOption()), ))
+        c = base.Config(schema=(('invalid_option', InvalidConfigOption()),))
 
         errors, warnings = c.validate()
 
         self.assertEqual(len(errors), 0)
-        self.assertEqual(warnings, [
-            ('invalid_option', 'pre_validation warning'),
-            ('invalid_option', 'run_validation warning'),
-            ('invalid_option', 'post_validation warning'),
-        ])
+        self.assertEqual(
+            warnings,
+            [
+                ('invalid_option', 'pre_validation warning'),
+                ('invalid_option', 'run_validation warning'),
+                ('invalid_option', 'post_validation warning'),
+            ],
+        )
 
     def test_load_from_file_with_relative_paths(self):
         """
diff --git a/mkdocs/tests/config/config_options_tests.py b/mkdocs/tests/config/config_options_tests.py
index e344aec3..fd605545 100644
--- a/mkdocs/tests/config/config_options_tests.py
+++ b/mkdocs/tests/config/config_options_tests.py
@@ -12,7 +12,6 @@ from mkdocs.utils import yaml_load
 
 
 class OptionallyRequiredTest(unittest.TestCase):
-
     def test_empty(self):
 
         option = config_options.OptionallyRequired()
@@ -49,7 +48,6 @@ class OptionallyRequiredTest(unittest.TestCase):
 
 
 class TypeTest(unittest.TestCase):
-
     def test_single_type(self):
 
         option = config_options.Type(str)
@@ -79,7 +77,6 @@ class TypeTest(unittest.TestCase):
 
 
 class ChoiceTest(unittest.TestCase):
-
     def test_valid_choice(self):
         option = config_options.Choice(('python', 'node'))
         value = option.validate('python')
@@ -97,7 +94,6 @@ class ChoiceTest(unittest.TestCase):
 
 
 class DeprecatedTest(unittest.TestCase):
-
     def test_deprecated_option_simple(self):
         option = config_options.Deprecated()
         option.pre_validation({'d': 'value'}, 'd')
@@ -164,7 +160,6 @@ class DeprecatedTest(unittest.TestCase):
 
 
 class IpAddressTest(unittest.TestCase):
-
     def test_valid_address(self):
         addr = '127.0.0.1:8000'
 
@@ -256,7 +251,6 @@ class IpAddressTest(unittest.TestCase):
 
 
 class URLTest(unittest.TestCase):
-
     def test_valid_url(self):
         option = config_options.URL()
 
@@ -288,7 +282,6 @@ class URLTest(unittest.TestCase):
 
 
 class RepoURLTest(unittest.TestCase):
-
     def test_repo_name_github(self):
 
         option = config_options.RepoURL()
@@ -351,14 +344,12 @@ class RepoURLTest(unittest.TestCase):
     def test_repo_name_custom_and_empty_edit_uri(self):
 
         option = config_options.RepoURL()
-        config = {'repo_url': "https://github.com/mkdocs/mkdocs",
-                  'repo_name': 'mkdocs'}
+        config = {'repo_url': "https://github.com/mkdocs/mkdocs", 'repo_name': 'mkdocs'}
         option.post_validation(config, 'repo_url')
         self.assertEqual(config.get('edit_uri'), 'edit/master/docs/')
 
 
 class DirTest(unittest.TestCase):
-
     def test_valid_dir(self):
 
         d = os.path.dirname(__file__)
@@ -403,7 +394,7 @@ class DirTest(unittest.TestCase):
         )
 
         test_config = {
-            'dir': 'юникод'
+            'dir': 'юникод',
         }
 
         cfg.load_dict(test_config)
@@ -421,7 +412,7 @@ class DirTest(unittest.TestCase):
         )
 
         test_config = {
-            'dir': 'Übersicht'.encode(encoding=sys.getfilesystemencoding())
+            'dir': 'Übersicht'.encode(encoding=sys.getfilesystemencoding()),
         }
 
         cfg.load_dict(test_config)
@@ -439,7 +430,7 @@ class DirTest(unittest.TestCase):
         )
 
         test_config = {
-            'dir': 'юникод'.encode(encoding='ISO 8859-5')
+            'dir': 'юникод'.encode(encoding='ISO 8859-5'),
         }
 
         cfg.load_dict(test_config)
@@ -457,7 +448,7 @@ class DirTest(unittest.TestCase):
         )
 
         test_config = {
-            'dir': 'foo'
+            'dir': 'foo',
         }
 
         cfg.load_dict(test_config)
@@ -476,7 +467,7 @@ class DirTest(unittest.TestCase):
         )
 
         test_config = {
-            'dir': '.'
+            'dir': '.',
         }
 
         cfg.load_dict(test_config)
@@ -488,7 +479,6 @@ class DirTest(unittest.TestCase):
 
 
 class ListOfPathsTest(unittest.TestCase):
-
     def test_valid_path(self):
         paths = [os.path.dirname(__file__)]
         option = config_options.ListOfPaths()
@@ -523,7 +513,7 @@ class ListOfPathsTest(unittest.TestCase):
             config_file_path=os.path.join(base_path, 'mkdocs.yml'),
         )
         test_config = {
-            'watch': ['foo']
+            'watch': ['foo'],
         }
         cfg.load_dict(test_config)
         fails, warns = cfg.validate()
@@ -534,9 +524,8 @@ class ListOfPathsTest(unittest.TestCase):
 
 
 class SiteDirTest(unittest.TestCase):
-
     def validate_config(self, config):
-        """ Given a config with values for site_dir and doc_dir, run site_dir post_validation. """
+        """Given a config with values for site_dir and doc_dir, run site_dir post_validation."""
         site_dir = config_options.SiteDir()
         docs_dir = config_options.Dir()
 
@@ -571,7 +560,7 @@ class SiteDirTest(unittest.TestCase):
             {'docs_dir': 'docs', 'site_dir': ''},
             {'docs_dir': '', 'site_dir': ''},
             {'docs_dir': j('..', parent_dir, 'docs'), 'site_dir': 'docs'},
-            {'docs_dir': 'docs', 'site_dir': '/'}
+            {'docs_dir': 'docs', 'site_dir': '/'},
         )
 
         for test_config in test_configs:
@@ -594,7 +583,7 @@ class SiteDirTest(unittest.TestCase):
                 self.validate_config(test_config)
 
     def test_common_prefix(self):
-        """ Legitimate settings with common prefixes should not fail validation. """
+        """Legitimate settings with common prefixes should not fail validation."""
 
         test_configs = (
             {'docs_dir': 'docs', 'site_dir': 'docs-site'},
@@ -606,7 +595,6 @@ class SiteDirTest(unittest.TestCase):
 
 
 class ThemeTest(unittest.TestCase):
-
     def test_theme_as_string(self):
 
         option = config_options.Theme()
@@ -627,7 +615,7 @@ class ThemeTest(unittest.TestCase):
     def test_theme_as_simple_config(self):
 
         config = {
-            'name': 'mkdocs'
+            'name': 'mkdocs',
         }
         option = config_options.Theme()
         value = option.validate(config)
@@ -639,7 +627,7 @@ class ThemeTest(unittest.TestCase):
             'name': 'mkdocs',
             'custom_dir': 'custom',
             'static_templates': ['sitemap.html'],
-            'show_sidebar': False
+            'show_sidebar': False,
         }
         option = config_options.Theme()
         value = option.validate(config)
@@ -648,7 +636,7 @@ class ThemeTest(unittest.TestCase):
     def test_theme_name_is_none(self):
 
         config = {
-            'name': None
+            'name': None,
         }
         option = config_options.Theme()
         value = option.validate(config)
@@ -666,7 +654,7 @@ class ThemeTest(unittest.TestCase):
     def test_uninstalled_theme_as_config(self):
 
         config = {
-            'name': 'mkdocs2'
+            'name': 'mkdocs2',
         }
         option = config_options.Theme()
         with self.assertRaises(config_options.ValidationError):
@@ -683,8 +671,8 @@ class ThemeTest(unittest.TestCase):
 
         config = {
             'theme': {
-                'name': None
-            }
+                'name': None,
+            },
         }
         option = config_options.Theme()
         with self.assertRaises(config_options.ValidationError):
@@ -697,7 +685,7 @@ class ThemeTest(unittest.TestCase):
             'theme': {
                 'name': None,
                 'custom_dir': abs_base_path + '/inexisting_custom_dir',
-            }
+            },
         }
         option = config_options.Theme()
         with self.assertRaises(config_options.ValidationError):
@@ -708,8 +696,8 @@ class ThemeTest(unittest.TestCase):
         config = {
             'theme': {
                 'name': 'mkdocs',
-                'locale': None
-            }
+                'locale': None,
+            },
         }
         option = config_options.Theme()
         with self.assertRaises(config_options.ValidationError):
@@ -720,8 +708,8 @@ class ThemeTest(unittest.TestCase):
         config = {
             'theme': {
                 'name': 'mkdocs',
-                'locale': 0
-            }
+                'locale': 0,
+            },
         }
         option = config_options.Theme()
         with self.assertRaises(config_options.ValidationError):
@@ -732,8 +720,8 @@ class ThemeTest(unittest.TestCase):
         config = {
             'theme': {
                 'name': 'mkdocs',
-                'locale': 'fr'
-            }
+                'locale': 'fr',
+            },
         }
         option = config_options.Theme()
         option.post_validation(config, 'theme')
@@ -741,19 +729,17 @@ class ThemeTest(unittest.TestCase):
 
 
 class NavTest(unittest.TestCase):
-
     def test_old_format(self):
         option = config_options.Nav()
         with self.assertRaises(config_options.ValidationError) as cm:
             option.validate([['index.md']])
-        self.assertEqual(str(cm.exception), "Expected nav item to be a string or dict, got a list: ['index.md']")
+        self.assertEqual(
+            str(cm.exception), "Expected nav item to be a string or dict, got a list: ['index.md']"
+        )
 
     def test_provided_dict(self):
         option = config_options.Nav()
-        value = option.validate([
-            'index.md',
-            {"Page": "page.md"}
-        ])
+        value = option.validate(['index.md', {"Page": "page.md"}])
         self.assertEqual(['index.md', {'Page': 'page.md'}], value)
 
         option.post_validation({'extra_stuff': []}, 'extra_stuff')
@@ -768,13 +754,17 @@ class NavTest(unittest.TestCase):
         self.assertEqual(option.warnings, [])
 
     def test_normal_nav(self):
-        nav = yaml_load(textwrap.dedent('''\
-            - Home: index.md
-            - getting-started.md
-            - User Guide:
-                - Overview: user-guide/index.md
-                - Installation: user-guide/installation.md
-        ''').encode())
+        nav = yaml_load(
+            textwrap.dedent(
+                '''\
+                - Home: index.md
+                - getting-started.md
+                - User Guide:
+                    - Overview: user-guide/index.md
+                    - Installation: user-guide/installation.md
+                '''
+            ).encode()
+        )
 
         option = config_options.Nav()
         self.assertEqual(option.validate(nav), nav)
@@ -796,7 +786,9 @@ class NavTest(unittest.TestCase):
         option = config_options.Nav()
         with self.assertRaises(config_options.ValidationError) as cm:
             option.validate([1])
-        self.assertEqual(str(cm.exception), "Expected nav item to be a string or dict, got a int: 1")
+        self.assertEqual(
+            str(cm.exception), "Expected nav item to be a string or dict, got a int: 1"
+        )
 
     def test_invalid_item_none(self):
         option = config_options.Nav()
@@ -821,14 +813,18 @@ class NavTest(unittest.TestCase):
         nav = ['foo', {}]
         with self.assertRaises(config_options.ValidationError) as cm:
             option.validate(nav)
-        self.assertEqual(str(cm.exception), "Expected nav item to be a dict of size 1, got a dict: {}")
+        self.assertEqual(
+            str(cm.exception), "Expected nav item to be a dict of size 1, got a dict: {}"
+        )
 
     def test_invalid_nested_list(self):
         option = config_options.Nav()
         nav = [{'aaa': [[{"bbb": "user-guide/index.md"}]]}]
         with self.assertRaises(config_options.ValidationError) as cm:
             option.validate(nav)
-        msg = "Expected nav item to be a string or dict, got a list: [{'bbb': 'user-guide/index.md'}]"
+        msg = (
+            "Expected nav item to be a string or dict, got a list: [{'bbb': 'user-guide/index.md'}]"
+        )
         self.assertEqual(str(cm.exception), msg)
 
     def test_invalid_children_oversized_dict(self):
@@ -842,11 +838,12 @@ class NavTest(unittest.TestCase):
     def test_warns_for_dict(self):
         option = config_options.Nav()
         option.validate([{"a": {"b": "c.md", "d": "e.md"}}])
-        self.assertEqual(option.warnings, ["Expected nav to be a list, got dict with keys ('b', 'd')"])
+        self.assertEqual(
+            option.warnings, ["Expected nav to be a list, got dict with keys ('b', 'd')"]
+        )
 
 
 class PrivateTest(unittest.TestCase):
-
     def test_defined(self):
 
         option = config_options.Private()
@@ -855,19 +852,21 @@ class PrivateTest(unittest.TestCase):
 
 
 class MarkdownExtensionsTest(unittest.TestCase):
-
     @patch('markdown.Markdown')
     def test_simple_list(self, mockMd):
         option = config_options.MarkdownExtensions()
         config = {
-            'markdown_extensions': ['foo', 'bar']
+            'markdown_extensions': ['foo', 'bar'],
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['foo', 'bar'],
-            'mdx_configs': {}
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['foo', 'bar'],
+                'mdx_configs': {},
+            },
+            config,
+        )
 
     @patch('markdown.Markdown')
     def test_list_dicts(self, mockMd):
@@ -876,18 +875,21 @@ class MarkdownExtensionsTest(unittest.TestCase):
             'markdown_extensions': [
                 {'foo': {'foo_option': 'foo value'}},
                 {'bar': {'bar_option': 'bar value'}},
-                {'baz': None}
+                {'baz': None},
             ]
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['foo', 'bar', 'baz'],
-            'mdx_configs': {
-                'foo': {'foo_option': 'foo value'},
-                'bar': {'bar_option': 'bar value'}
-            }
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['foo', 'bar', 'baz'],
+                'mdx_configs': {
+                    'foo': {'foo_option': 'foo value'},
+                    'bar': {'bar_option': 'bar value'},
+                },
+            },
+            config,
+        )
 
     @patch('markdown.Markdown')
     def test_mixed_list(self, mockMd):
@@ -895,17 +897,20 @@ class MarkdownExtensionsTest(unittest.TestCase):
         config = {
             'markdown_extensions': [
                 'foo',
-                {'bar': {'bar_option': 'bar value'}}
+                {'bar': {'bar_option': 'bar value'}},
             ]
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['foo', 'bar'],
-            'mdx_configs': {
-                'bar': {'bar_option': 'bar value'}
-            }
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['foo', 'bar'],
+                'mdx_configs': {
+                    'bar': {'bar_option': 'bar value'},
+                },
+            },
+            config,
+        )
 
     @patch('markdown.Markdown')
     def test_dict_of_dicts(self, mockMd):
@@ -914,86 +919,104 @@ class MarkdownExtensionsTest(unittest.TestCase):
             'markdown_extensions': {
                 'foo': {'foo_option': 'foo value'},
                 'bar': {'bar_option': 'bar value'},
-                'baz': {}
+                'baz': {},
             }
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['foo', 'bar', 'baz'],
-            'mdx_configs': {
-                'foo': {'foo_option': 'foo value'},
-                'bar': {'bar_option': 'bar value'}
-            }
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['foo', 'bar', 'baz'],
+                'mdx_configs': {
+                    'foo': {'foo_option': 'foo value'},
+                    'bar': {'bar_option': 'bar value'},
+                },
+            },
+            config,
+        )
 
     @patch('markdown.Markdown')
     def test_builtins(self, mockMd):
         option = config_options.MarkdownExtensions(builtins=['meta', 'toc'])
         config = {
-            'markdown_extensions': ['foo', 'bar']
+            'markdown_extensions': ['foo', 'bar'],
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['meta', 'toc', 'foo', 'bar'],
-            'mdx_configs': {}
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['meta', 'toc', 'foo', 'bar'],
+                'mdx_configs': {},
+            },
+            config,
+        )
 
     def test_duplicates(self):
         option = config_options.MarkdownExtensions(builtins=['meta', 'toc'])
         config = {
-            'markdown_extensions': ['meta', 'toc']
+            'markdown_extensions': ['meta', 'toc'],
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['meta', 'toc'],
-            'mdx_configs': {}
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['meta', 'toc'],
+                'mdx_configs': {},
+            },
+            config,
+        )
 
     def test_builtins_config(self):
         option = config_options.MarkdownExtensions(builtins=['meta', 'toc'])
         config = {
             'markdown_extensions': [
-                {'toc': {'permalink': True}}
-            ]
+                {'toc': {'permalink': True}},
+            ],
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['meta', 'toc'],
-            'mdx_configs': {'toc': {'permalink': True}}
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['meta', 'toc'],
+                'mdx_configs': {'toc': {'permalink': True}},
+            },
+            config,
+        )
 
     @patch('markdown.Markdown')
     def test_configkey(self, mockMd):
         option = config_options.MarkdownExtensions(configkey='bar')
         config = {
             'markdown_extensions': [
-                {'foo': {'foo_option': 'foo value'}}
+                {'foo': {'foo_option': 'foo value'}},
             ]
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': ['foo'],
-            'bar': {
-                'foo': {'foo_option': 'foo value'}
-            }
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': ['foo'],
+                'bar': {
+                    'foo': {'foo_option': 'foo value'},
+                },
+            },
+            config,
+        )
 
     def test_none(self):
         option = config_options.MarkdownExtensions(default=[])
         config = {
-            'markdown_extensions': None
+            'markdown_extensions': None,
         }
         config['markdown_extensions'] = option.validate(config['markdown_extensions'])
         option.post_validation(config, 'markdown_extensions')
-        self.assertEqual({
-            'markdown_extensions': [],
-            'mdx_configs': {}
-        }, config)
+        self.assertEqual(
+            {
+                'markdown_extensions': [],
+                'mdx_configs': {},
+            },
+            config,
+        )
 
     @patch('markdown.Markdown')
     def test_not_list(self, mockMd):
@@ -1006,8 +1029,8 @@ class MarkdownExtensionsTest(unittest.TestCase):
         option = config_options.MarkdownExtensions()
         config = {
             'markdown_extensions': [
-                {'foo': 'not a dict'}
-            ]
+                {'foo': 'not a dict'},
+            ],
         }
         with self.assertRaises(config_options.ValidationError):
             option.validate(config['markdown_extensions'])
@@ -1017,8 +1040,8 @@ class MarkdownExtensionsTest(unittest.TestCase):
         option = config_options.MarkdownExtensions()
         config = {
             'markdown_extensions': [
-                ['not a dict']
-            ]
+                ['not a dict'],
+            ],
         }
         with self.assertRaises(config_options.ValidationError):
             option.validate(config['markdown_extensions'])
@@ -1028,8 +1051,8 @@ class MarkdownExtensionsTest(unittest.TestCase):
         option = config_options.MarkdownExtensions()
         config = {
             'markdown_extensions': [
-                {'key1': 'value', 'key2': 'too many keys'}
-            ]
+                {'key1': 'value', 'key2': 'too many keys'},
+            ],
         }
         with self.assertRaises(config_options.ValidationError):
             option.validate(config['markdown_extensions'])
@@ -1037,7 +1060,7 @@ class MarkdownExtensionsTest(unittest.TestCase):
     def test_unknown_extension(self):
         option = config_options.MarkdownExtensions()
         config = {
-            'markdown_extensions': ['unknown']
+            'markdown_extensions': ['unknown'],
         }
         with self.assertRaises(config_options.ValidationError):
             option.validate(config['markdown_extensions'])
diff --git a/mkdocs/tests/config/config_tests.py b/mkdocs/tests/config/config_tests.py
index 295a9bd4..fe24fd3a 100644
--- a/mkdocs/tests/config/config_tests.py
+++ b/mkdocs/tests/config/config_tests.py
@@ -38,11 +38,13 @@ class ConfigTests(unittest.TestCase):
             config.load_config(config_file='/path/that/is/not/real')
 
     def test_invalid_config(self):
-        file_contents = dedent("""
-        - ['index.md', 'Introduction']
-        - ['index.md', 'Introduction']
-        - ['index.md', 'Introduction']
-        """)
+        file_contents = dedent(
+            """
+            - ['index.md', 'Introduction']
+            - ['index.md', 'Introduction']
+            - ['index.md', 'Introduction']
+            """
+        )
         config_file = tempfile.NamedTemporaryFile('w', delete=False)
         try:
             config_file.write(file_contents)
@@ -61,15 +63,15 @@ class ConfigTests(unittest.TestCase):
         """
         expected_result = {
             'site_name': 'Example',
-            'nav': [
-                {'Introduction': 'index.md'}
-            ],
+            'nav': [{'Introduction': 'index.md'}],
         }
-        file_contents = dedent("""
-        site_name: Example
-        nav:
-        - 'Introduction': 'index.md'
-        """)
+        file_contents = dedent(
+            """
+            site_name: Example
+            nav:
+            - 'Introduction': 'index.md'
+            """
+        )
         with TemporaryDirectory() as temp_path:
             os.mkdir(os.path.join(temp_path, 'docs'))
             config_path = os.path.join(temp_path, 'mkdocs.yml')
@@ -90,16 +92,18 @@ class ConfigTests(unittest.TestCase):
                 {"theme": "readthedocs"},  # builtin theme
                 {"theme": {'name': 'readthedocs'}},  # builtin as complex
                 {"theme": {'name': None, 'custom_dir': mytheme}},  # custom only as complex
-                {"theme": {'name': 'readthedocs', 'custom_dir': custom}},  # builtin and custom as complex
+                {
+                    "theme": {'name': 'readthedocs', 'custom_dir': custom}
+                },  # builtin and custom as complex
                 {  # user defined variables
                     'theme': {
                         'name': 'mkdocs',
                         'locale': 'fr',
                         'static_templates': ['foo.html'],
                         'show_sidebar': False,
-                        'some_var': 'bar'
+                        'some_var': 'bar',
                     }
-                }
+                },
             ]
 
             mkdocs_dir = os.path.abspath(os.path.dirname(mkdocs.__file__))
@@ -120,9 +124,10 @@ class ConfigTests(unittest.TestCase):
                         'hljs_languages': [],
                         'navigation_depth': 2,
                         'nav_style': 'primary',
-                        'shortcuts': {'help': 191, 'next': 78, 'previous': 80, 'search': 83}
-                    }
-                }, {
+                        'shortcuts': {'help': 191, 'next': 78, 'previous': 80, 'search': 83},
+                    },
+                },
+                {
                     'dirs': [os.path.join(theme_dir, 'readthedocs'), mkdocs_templates_dir],
                     'static_templates': ['404.html', 'sitemap.xml'],
                     'vars': {
@@ -138,9 +143,10 @@ class ConfigTests(unittest.TestCase):
                         'sticky_navigation': True,
                         'logo': None,
                         'titles_only': False,
-                        'collapse_navigation': True
-                    }
-                }, {
+                        'collapse_navigation': True,
+                    },
+                },
+                {
                     'dirs': [os.path.join(theme_dir, 'readthedocs'), mkdocs_templates_dir],
                     'static_templates': ['404.html', 'sitemap.xml'],
                     'vars': {
@@ -156,13 +162,15 @@ class ConfigTests(unittest.TestCase):
                         'sticky_navigation': True,
                         'logo': None,
                         'titles_only': False,
-                        'collapse_navigation': True
-                    }
-                }, {
+                        'collapse_navigation': True,
+                    },
+                },
+                {
                     'dirs': [mytheme, mkdocs_templates_dir],
                     'static_templates': ['sitemap.xml'],
-                    'vars': {'locale': parse_locale('en')}
-                }, {
+                    'vars': {'locale': parse_locale('en')},
+                },
+                {
                     'dirs': [custom, os.path.join(theme_dir, 'readthedocs'), mkdocs_templates_dir],
                     'static_templates': ['404.html', 'sitemap.xml'],
                     'vars': {
@@ -178,9 +186,10 @@ class ConfigTests(unittest.TestCase):
                         'sticky_navigation': True,
                         'logo': None,
                         'titles_only': False,
-                        'collapse_navigation': True
-                    }
-                }, {
+                        'collapse_navigation': True,
+                    },
+                },
+                {
                     'dirs': [os.path.join(theme_dir, 'mkdocs'), mkdocs_templates_dir],
                     'static_templates': ['404.html', 'sitemap.xml', 'foo.html'],
                     'vars': {
@@ -195,9 +204,9 @@ class ConfigTests(unittest.TestCase):
                         'hljs_languages': [],
                         'navigation_depth': 2,
                         'nav_style': 'primary',
-                        'shortcuts': {'help': 191, 'next': 78, 'previous': 80, 'search': 83}
-                    }
-                }
+                        'shortcuts': {'help': 191, 'next': 78, 'previous': 80, 'search': 83},
+                    },
+                },
             )
 
             for config_contents, result in zip(configs, results):
@@ -212,25 +221,29 @@ class ConfigTests(unittest.TestCase):
 
     def test_empty_nav(self):
         conf = config.Config(schema=defaults.get_schema())
-        conf.load_dict({
-            'site_name': 'Example',
-            'config_file_path': os.path.join(os.path.abspath('.'), 'mkdocs.yml')
-        })
+        conf.load_dict(
+            {
+                'site_name': 'Example',
+                'config_file_path': os.path.join(os.path.abspath('.'), 'mkdocs.yml'),
+            }
+        )
         conf.validate()
         self.assertEqual(conf['nav'], None)
 
     def test_error_on_pages(self):
         conf = config.Config(schema=defaults.get_schema())
-        conf.load_dict({
-            'site_name': 'Example',
-            'pages': ['index.md', 'about.md'],
-        })
+        conf.load_dict(
+            {
+                'site_name': 'Example',
+                'pages': ['index.md', 'about.md'],
+            }
+        )
         errors, warnings = conf.validate()
         self.assertEqual(warnings, [])
         self.assertEqual(len(errors), 1)
         self.assertEqual(
             str(errors[0][1]),
-            "The configuration option 'pages' was removed from MkDocs. Use 'nav' instead."
+            "The configuration option 'pages' was removed from MkDocs. Use 'nav' instead.",
         )
 
     def test_doc_dir_in_site_dir(self):
@@ -247,7 +260,7 @@ class ConfigTests(unittest.TestCase):
         )
 
         conf = {
-            'config_file_path': j(os.path.abspath('..'), 'mkdocs.yml')
+            'config_file_path': j(os.path.abspath('..'), 'mkdocs.yml'),
         }
 
         for test_config in test_configs:
@@ -256,11 +269,13 @@ class ConfigTests(unittest.TestCase):
             patch.update(test_config)
 
             # Same as the default schema, but don't verify the docs_dir exists.
-            c = config.Config(schema=(
-                ('docs_dir', config_options.Dir(default='docs')),
-                ('site_dir', config_options.SiteDir(default='site')),
-                ('config_file_path', config_options.Type(str))
-            ))
+            c = config.Config(
+                schema=(
+                    ('docs_dir', config_options.Dir(default='docs')),
+                    ('site_dir', config_options.SiteDir(default='site')),
+                    ('config_file_path', config_options.Type(str)),
+                )
+            )
             c.load_dict(patch)
 
             errors, warnings = c.validate()
diff --git a/mkdocs/tests/gh_deploy_tests.py b/mkdocs/tests/gh_deploy_tests.py
index 4670e21a..45acd044 100644
--- a/mkdocs/tests/gh_deploy_tests.py
+++ b/mkdocs/tests/gh_deploy_tests.py
@@ -9,7 +9,6 @@ from mkdocs import __version__
 
 
 class TestGitHubDeploy(unittest.TestCase):
-
     @mock.patch('subprocess.Popen')
     def test_is_cwd_git_repo(self, mock_popeno):
 
@@ -36,7 +35,7 @@ class TestGitHubDeploy(unittest.TestCase):
 
         mock_popeno().communicate.return_value = (
             b'git@github.com:mkdocs/mkdocs.git\n',
-            b''
+            b'',
         )
 
         expected = ('git@', 'mkdocs/mkdocs.git')
@@ -47,7 +46,7 @@ class TestGitHubDeploy(unittest.TestCase):
 
         mock_popeno().communicate.return_value = (
             b'https://github.com/mkdocs/mkdocs.git\n',
-            b''
+            b'',
         )
 
         expected = ('https://', 'mkdocs/mkdocs.git')
@@ -58,7 +57,7 @@ class TestGitHubDeploy(unittest.TestCase):
 
         mock_popeno().communicate.return_value = (
             b'https://notgh.com/mkdocs/mkdocs.git\n',
-            b''
+            b'',
         )
 
         expected = (None, None)
@@ -82,8 +81,9 @@ class TestGitHubDeploy(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy._check_version')
     @mock.patch('ghp_import.ghp_import')
     @mock.patch('os.path.isfile', return_value=False)
-    def test_deploy_no_cname(self, mock_isfile, mock_import, check_version, get_remote,
-                             get_sha, is_repo):
+    def test_deploy_no_cname(
+        self, mock_isfile, mock_import, check_version, get_remote, get_sha, is_repo
+    ):
 
         config = load_config(
             remote_branch='test',
@@ -92,8 +92,9 @@ class TestGitHubDeploy(unittest.TestCase):
 
     @mock.patch('mkdocs.commands.gh_deploy._is_cwd_git_repo', return_value=True)
     @mock.patch('mkdocs.commands.gh_deploy._get_current_sha', return_value='shashas')
-    @mock.patch('mkdocs.commands.gh_deploy._get_remote_url', return_value=(
-        'git@', 'mkdocs/mkdocs.git'))
+    @mock.patch(
+        'mkdocs.commands.gh_deploy._get_remote_url', return_value=('git@', 'mkdocs/mkdocs.git')
+    )
     @mock.patch('mkdocs.commands.gh_deploy._check_version')
     @mock.patch('ghp_import.ghp_import')
     def test_deploy_hostname(self, mock_import, check_version, get_remote, get_sha, is_repo):
@@ -108,7 +109,9 @@ class TestGitHubDeploy(unittest.TestCase):
     @mock.patch('mkdocs.commands.gh_deploy._get_remote_url', return_value=(None, None))
     @mock.patch('mkdocs.commands.gh_deploy._check_version')
     @mock.patch('ghp_import.ghp_import')
-    def test_deploy_ignore_version_default(self, mock_import, check_version, get_remote, get_sha, is_repo):
+    def test_deploy_ignore_version_default(
+        self, mock_import, check_version, get_remote, get_sha, is_repo
+    ):
 
         config = load_config(
             remote_branch='test',
@@ -150,31 +153,42 @@ class TestGitHubDeploy(unittest.TestCase):
 
 
 class TestGitHubDeployLogs(unittest.TestCase):
-
     @mock.patch('subprocess.Popen')
     def test_mkdocs_newer(self, mock_popeno):
 
-        mock_popeno().communicate.return_value = (b'Deployed 12345678 with MkDocs version: 0.1.2\n', b'')
+        mock_popeno().communicate.return_value = (
+            b'Deployed 12345678 with MkDocs version: 0.1.2\n',
+            b'',
+        )
 
         with self.assertLogs('mkdocs', level='INFO') as cm:
             gh_deploy._check_version('gh-pages')
         self.assertEqual(
-            cm.output, ['INFO:mkdocs.commands.gh_deploy:Previous deployment was done with MkDocs '
-                        f'version 0.1.2; you are deploying with a newer version ({__version__})']
+            cm.output,
+            [
+                'INFO:mkdocs.commands.gh_deploy:Previous deployment was done with MkDocs '
+                f'version 0.1.2; you are deploying with a newer version ({__version__})'
+            ],
         )
 
     @mock.patch('subprocess.Popen')
     def test_mkdocs_older(self, mock_popeno):
 
-        mock_popeno().communicate.return_value = (b'Deployed 12345678 with MkDocs version: 10.1.2\n', b'')
+        mock_popeno().communicate.return_value = (
+            b'Deployed 12345678 with MkDocs version: 10.1.2\n',
+            b'',
+        )
 
         with self.assertLogs('mkdocs', level='ERROR') as cm:
             with self.assertRaises(Abort):
                 gh_deploy._check_version('gh-pages')
         self.assertEqual(
-            cm.output, ['ERROR:mkdocs.commands.gh_deploy:Deployment terminated: Previous deployment was made with '
-                        f'MkDocs version 10.1.2; you are attempting to deploy with an older version ({__version__}).'
-                        ' Use --ignore-version to deploy anyway.']
+            cm.output,
+            [
+                'ERROR:mkdocs.commands.gh_deploy:Deployment terminated: Previous deployment was made with '
+                f'MkDocs version 10.1.2; you are attempting to deploy with an older version ({__version__}).'
+                ' Use --ignore-version to deploy anyway.'
+            ],
         )
 
     @mock.patch('subprocess.Popen')
@@ -186,5 +200,7 @@ class TestGitHubDeployLogs(unittest.TestCase):
             gh_deploy._check_version('gh-pages')
         self.assertEqual(
             cm.output,
-            ['WARNING:mkdocs.commands.gh_deploy:Version check skipped: No version specified in previous deployment.']
+            [
+                'WARNING:mkdocs.commands.gh_deploy:Version check skipped: No version specified in previous deployment.'
+            ],
         )
diff --git a/mkdocs/tests/integration.py b/mkdocs/tests/integration.py
index ebbe8897..4b594f1c 100644
--- a/mkdocs/tests/integration.py
+++ b/mkdocs/tests/integration.py
@@ -31,21 +31,22 @@ TEST_PROJECTS = os.path.abspath(os.path.join(DIR, 'integration'))
 
 
 @click.command()
-@click.option('--output',
-              help="The output directory to use when building themes",
-              type=click.Path(file_okay=False, writable=True),
-              required=True)
+@click.option(
+    '--output',
+    help="The output directory to use when building themes",
+    type=click.Path(file_okay=False, writable=True),
+    required=True,
+)
 def main(output=None):
 
     log.propagate = False
     stream = logging.StreamHandler()
-    formatter = logging.Formatter(
-        "\033[1m\033[1;32m *** %(message)s *** \033[0m")
+    formatter = logging.Formatter("\033[1m\033[1;32m *** %(message)s *** \033[0m")
     stream.setFormatter(formatter)
     log.addHandler(stream)
     log.setLevel(logging.DEBUG)
 
-    base_cmd = ['mkdocs', 'build', '-s', '-v', '--site-dir', ]
+    base_cmd = ['mkdocs', 'build', '-s', '-v', '--site-dir']
 
     log.debug("Building installed themes.")
     for theme in sorted(MKDOCS_THEMES):
@@ -60,7 +61,7 @@ def main(output=None):
         log.debug(f"Building test project: {project}")
         project_dir = os.path.join(TEST_PROJECTS, project)
         out = os.path.join(output, project)
-        command = base_cmd + [out, ]
+        command = base_cmd + [out]
         subprocess.check_call(command, cwd=project_dir)
 
     log.debug(f"Theme and integration builds are in {output}")
diff --git a/mkdocs/tests/livereload_tests.py b/mkdocs/tests/livereload_tests.py
index ecbbaecc..6d838c14 100644
--- a/mkdocs/tests/livereload_tests.py
+++ b/mkdocs/tests/livereload_tests.py
@@ -64,9 +64,7 @@ def do_request(server, content):
     return headers, content.decode()
 
 
-SCRIPT_REGEX = (
-    r'<script>[\S\s]+?livereload\([0-9]+, [0-9]+\);\s*</script>'
-)
+SCRIPT_REGEX = r'<script>[\S\s]+?livereload\([0-9]+, [0-9]+\);\s*</script>'
 
 
 class BuildTests(unittest.TestCase):
diff --git a/mkdocs/tests/localization_tests.py b/mkdocs/tests/localization_tests.py
index a7ceff96..d7312c6c 100644
--- a/mkdocs/tests/localization_tests.py
+++ b/mkdocs/tests/localization_tests.py
@@ -9,7 +9,6 @@ from mkdocs.config.base import ValidationError
 
 
 class LocalizationTests(unittest.TestCase):
-
     def setUp(self):
         self.env = unittest.mock.Mock()
 
@@ -42,7 +41,9 @@ class LocalizationTests(unittest.TestCase):
     def test_translations_found(self, tdir):
         translations = unittest.mock.Mock()
 
-        with unittest.mock.patch('mkdocs.localization.Translations.load', return_value=translations):
+        with unittest.mock.patch(
+            'mkdocs.localization.Translations.load', return_value=translations
+        ):
             install_translations(self.env, parse_locale('en'), [tdir])
 
         self.env.install_gettext_translations.assert_called_once_with(translations)
diff --git a/mkdocs/tests/new_tests.py b/mkdocs/tests/new_tests.py
index 735fdf5d..3406c296 100644
--- a/mkdocs/tests/new_tests.py
+++ b/mkdocs/tests/new_tests.py
@@ -8,7 +8,6 @@ from mkdocs.commands import new
 
 
 class NewTests(unittest.TestCase):
-
     def test_new(self):
 
         tempdir = tempfile.mkdtemp()
diff --git a/mkdocs/tests/plugin_tests.py b/mkdocs/tests/plugin_tests.py
index fa0e3d08..e204c91f 100644
--- a/mkdocs/tests/plugin_tests.py
+++ b/mkdocs/tests/plugin_tests.py
@@ -21,24 +21,23 @@ class DummyPlugin(plugins.BasePlugin):
     )
 
     def on_pre_page(self, content, **kwargs):
-        """ modify page content by prepending `foo` config value. """
+        """modify page content by prepending `foo` config value."""
         return f'{self.config["foo"]} {content}'
 
     def on_nav(self, item, **kwargs):
-        """ do nothing (return None) to not modify item. """
+        """do nothing (return None) to not modify item."""
         return None
 
     def on_page_read_source(self, **kwargs):
-        """ create new source by prepending `foo` config value to 'source'. """
+        """create new source by prepending `foo` config value to 'source'."""
         return f'{self.config["foo"]} source'
 
     def on_pre_build(self, **kwargs):
-        """ do nothing (return None). """
+        """do nothing (return None)."""
         return None
 
 
 class TestPluginClass(unittest.TestCase):
-
     def test_valid_plugin_options(self):
         test_dir = 'test'
 
@@ -85,7 +84,6 @@ class TestPluginClass(unittest.TestCase):
 
 
 class TestPluginCollection(unittest.TestCase):
-
     def test_set_plugin_on_collection(self):
         collection = plugins.PluginCollection()
         plugin = DummyPlugin()
@@ -98,7 +96,9 @@ class TestPluginCollection(unittest.TestCase):
         collection['foo'] = plugin1
         plugin2 = DummyPlugin()
         collection['bar'] = plugin2
-        self.assertEqual([(k, v) for k, v in collection.items()], [('foo', plugin1), ('bar', plugin2)])
+        self.assertEqual(
+            [(k, v) for k, v in collection.items()], [('foo', plugin1), ('bar', plugin2)]
+        )
 
     def test_run_event_on_collection(self):
         collection = plugins.PluginCollection()
@@ -115,8 +115,9 @@ class TestPluginCollection(unittest.TestCase):
         plugin2 = DummyPlugin()
         plugin2.load_config({'foo': 'second'})
         collection['bar'] = plugin2
-        self.assertEqual(collection.run_event('pre_page', 'page content'),
-                         'second new page content')
+        self.assertEqual(
+            collection.run_event('pre_page', 'page content'), 'second new page content'
+        )
 
     def test_event_returns_None(self):
         collection = plugins.PluginCollection()
@@ -214,7 +215,6 @@ MockEntryPoint.configure_mock(**{'name': 'sample', 'load.return_value': DummyPlu
 
 @mock.patch('importlib_metadata.entry_points', return_value=[MockEntryPoint])
 class TestPluginConfig(unittest.TestCase):
-
     def test_plugin_config_without_options(self, mock_class):
 
         cfg = {'plugins': ['sample']}
@@ -234,12 +234,14 @@ class TestPluginConfig(unittest.TestCase):
     def test_plugin_config_with_options(self, mock_class):
 
         cfg = {
-            'plugins': [{
-                'sample': {
-                    'foo': 'foo value',
-                    'bar': 42
+            'plugins': [
+                {
+                    'sample': {
+                        'foo': 'foo value',
+                        'bar': 42,
+                    },
                 }
-            }]
+            ],
         }
         option = config.config_options.Plugins()
         cfg['plugins'] = option.validate(cfg['plugins'])
@@ -260,9 +262,9 @@ class TestPluginConfig(unittest.TestCase):
             'plugins': {
                 'sample': {
                     'foo': 'foo value',
-                    'bar': 42
-                }
-            }
+                    'bar': 42,
+                },
+            },
         }
         option = config.config_options.Plugins()
         cfg['plugins'] = option.validate(cfg['plugins'])
@@ -335,13 +337,15 @@ class TestPluginConfig(unittest.TestCase):
     def test_plugin_config_multivalue_dict(self, mock_class):
 
         cfg = {
-            'plugins': [{
-                'sample': {
-                    'foo': 'foo value',
-                    'bar': 42
-                },
-                'extra_key': 'baz'
-            }]
+            'plugins': [
+                {
+                    'sample': {
+                        'foo': 'foo value',
+                        'bar': 42,
+                    },
+                    'extra_key': 'baz',
+                }
+            ],
         }
         option = config.config_options.Plugins()
         with self.assertRaises(config.base.ValidationError):
@@ -350,7 +354,7 @@ class TestPluginConfig(unittest.TestCase):
     def test_plugin_config_not_string_or_dict(self, mock_class):
 
         cfg = {
-            'plugins': [('not a string or dict',)]
+            'plugins': [('not a string or dict',)],
         }
         option = config.config_options.Plugins()
         with self.assertRaises(config.base.ValidationError):
@@ -359,9 +363,11 @@ class TestPluginConfig(unittest.TestCase):
     def test_plugin_config_options_not_dict(self, mock_class):
 
         cfg = {
-            'plugins': [{
-                'sample': 'not a dict'
-            }]
+            'plugins': [
+                {
+                    'sample': 'not a dict',
+                }
+            ],
         }
         option = config.config_options.Plugins()
         with self.assertRaises(config.base.ValidationError):
diff --git a/mkdocs/tests/search_tests.py b/mkdocs/tests/search_tests.py
index a7a33917..654a4cae 100644
--- a/mkdocs/tests/search_tests.py
+++ b/mkdocs/tests/search_tests.py
@@ -18,7 +18,6 @@ def strip_whitespace(string):
 
 
 class SearchConfigTests(unittest.TestCase):
-
     def test_lang_default(self):
         option = search.LangOption(default=['en'])
         value = option.validate(None)
@@ -76,14 +75,13 @@ class SearchConfigTests(unittest.TestCase):
 
 
 class SearchPluginTests(unittest.TestCase):
-
     def test_plugin_config_defaults(self):
         expected = {
             'lang': None,
             'separator': r'[\s\-]+',
             'min_search_length': 3,
             'prebuild_index': False,
-            'indexing': 'full'
+            'indexing': 'full',
         }
         plugin = search.SearchPlugin()
         errors, warnings = plugin.load_config({})
@@ -97,7 +95,7 @@ class SearchPluginTests(unittest.TestCase):
             'separator': r'[\s\-]+',
             'min_search_length': 3,
             'prebuild_index': False,
-            'indexing': 'full'
+            'indexing': 'full',
         }
         plugin = search.SearchPlugin()
         errors, warnings = plugin.load_config({'lang': 'es'})
@@ -111,7 +109,7 @@ class SearchPluginTests(unittest.TestCase):
             'separator': r'[\s\-\.]+',
             'min_search_length': 3,
             'prebuild_index': False,
-            'indexing': 'full'
+            'indexing': 'full',
         }
         plugin = search.SearchPlugin()
         errors, warnings = plugin.load_config({'separator': r'[\s\-\.]+'})
@@ -125,7 +123,7 @@ class SearchPluginTests(unittest.TestCase):
             'separator': r'[\s\-]+',
             'min_search_length': 2,
             'prebuild_index': False,
-            'indexing': 'full'
+            'indexing': 'full',
         }
         plugin = search.SearchPlugin()
         errors, warnings = plugin.load_config({'min_search_length': 2})
@@ -139,7 +137,7 @@ class SearchPluginTests(unittest.TestCase):
             'separator': r'[\s\-]+',
             'min_search_length': 3,
             'prebuild_index': True,
-            'indexing': 'full'
+            'indexing': 'full',
         }
         plugin = search.SearchPlugin()
         errors, warnings = plugin.load_config({'prebuild_index': True})
@@ -153,7 +151,7 @@ class SearchPluginTests(unittest.TestCase):
             'separator': r'[\s\-]+',
             'min_search_length': 3,
             'prebuild_index': False,
-            'indexing': 'titles'
+            'indexing': 'titles',
         }
         plugin = search.SearchPlugin()
         errors, warnings = plugin.load_config({'indexing': 'titles'})
@@ -186,7 +184,9 @@ class SearchPluginTests(unittest.TestCase):
     def test_event_on_config_theme_locale(self):
         plugin = search.SearchPlugin()
         plugin.load_config({})
-        result = plugin.on_config(load_config(theme={'name': 'mkdocs', 'locale': 'fr'}, extra_javascript=[]))
+        result = plugin.on_config(
+            load_config(theme={'name': 'mkdocs', 'locale': 'fr'}, extra_javascript=[])
+        )
         self.assertFalse(result['theme']['search_index_only'])
         self.assertFalse(result['theme']['include_search_page'])
         self.assertEqual(result['theme'].static_templates, {'404.html', 'sitemap.xml'})
@@ -197,18 +197,24 @@ class SearchPluginTests(unittest.TestCase):
     def test_event_on_config_include_search_page(self):
         plugin = search.SearchPlugin()
         plugin.load_config({})
-        config = load_config(theme={'name': 'mkdocs', 'include_search_page': True}, extra_javascript=[])
+        config = load_config(
+            theme={'name': 'mkdocs', 'include_search_page': True}, extra_javascript=[]
+        )
         result = plugin.on_config(config)
         self.assertFalse(result['theme']['search_index_only'])
         self.assertTrue(result['theme']['include_search_page'])
-        self.assertEqual(result['theme'].static_templates, {'404.html', 'sitemap.xml', 'search.html'})
+        self.assertEqual(
+            result['theme'].static_templates, {'404.html', 'sitemap.xml', 'search.html'}
+        )
         self.assertEqual(len(result['theme'].dirs), 3)
         self.assertEqual(result['extra_javascript'], ['search/main.js'])
 
     def test_event_on_config_search_index_only(self):
         plugin = search.SearchPlugin()
         plugin.load_config({})
-        config = load_config(theme={'name': 'mkdocs', 'search_index_only': True}, extra_javascript=[])
+        config = load_config(
+            theme={'name': 'mkdocs', 'search_index_only': True}, extra_javascript=[]
+        )
         result = plugin.on_config(config)
         self.assertTrue(result['theme']['search_index_only'])
         self.assertFalse(result['theme']['include_search_page'])
@@ -263,7 +269,6 @@ class SearchPluginTests(unittest.TestCase):
 
 
 class SearchIndexTests(unittest.TestCase):
-
     def test_html_stripping(self):
 
         stripper = search_index.ContentParser()
@@ -279,11 +284,9 @@ class SearchIndexTests(unittest.TestCase):
         parser.feed('<h1 id="title">Title</h1>TEST')
         parser.close()
 
-        self.assertEqual(parser.data, [search_index.ContentSection(
-            text=["TEST"],
-            id_="title",
-            title="Title"
-        )])
+        self.assertEqual(
+            parser.data, [search_index.ContentSection(text=["TEST"], id_="title", title="Title")]
+        )
 
     def test_content_parser_no_id(self):
 
@@ -292,11 +295,9 @@ class SearchIndexTests(unittest.TestCase):
         parser.feed("<h1>Title</h1>TEST")
         parser.close()
 
-        self.assertEqual(parser.data, [search_index.ContentSection(
-            text=["TEST"],
-            id_=None,
-            title="Title"
-        )])
+        self.assertEqual(
+            parser.data, [search_index.ContentSection(text=["TEST"], id_=None, title="Title")]
+        )
 
     def test_content_parser_content_before_header(self):
 
@@ -305,11 +306,9 @@ class SearchIndexTests(unittest.TestCase):
         parser.feed("Content Before H1 <h1>Title</h1>TEST")
         parser.close()
 
-        self.assertEqual(parser.data, [search_index.ContentSection(
-            text=["TEST"],
-            id_=None,
-            title="Title"
-        )])
+        self.assertEqual(
+            parser.data, [search_index.ContentSection(text=["TEST"], id_=None, title="Title")]
+        )
 
     def test_content_parser_no_sections(self):
 
@@ -326,11 +325,13 @@ class SearchIndexTests(unittest.TestCase):
 
         index = search_index.SearchIndex()
 
-        md = dedent("""
-        # Heading 1
-        ## Heading 2
-        ### Heading 3
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 2
+            ### Heading 3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
 
         toc_item = index._find_toc_by_id(toc, "heading-1")
@@ -364,23 +365,29 @@ class SearchIndexTests(unittest.TestCase):
                     'index.md',
                     base_cfg['docs_dir'],
                     base_cfg['site_dir'],
-                    base_cfg['use_directory_urls']),
-                base_cfg),
+                    base_cfg['use_directory_urls'],
+                ),
+                base_cfg,
+            ),
             Page(
                 'About',
                 File(
                     'about.md',
                     base_cfg['docs_dir'],
                     base_cfg['site_dir'],
-                    base_cfg['use_directory_urls']),
-                base_cfg)
+                    base_cfg['use_directory_urls'],
+                ),
+                base_cfg,
+            ),
         ]
 
-        md = dedent("""
-        # Heading 1
-        ## Heading 2
-        ### Heading 3
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 2
+            ### Heading 3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
 
         full_content = ''.join(f"Heading{i}Content{i}" for i in range(1, 4))
@@ -420,12 +427,12 @@ class SearchIndexTests(unittest.TestCase):
     def test_search_indexing_options(self):
         def test_page(title, filename, config):
             test_page = Page(
-                title, File(
-                    filename,
-                    config['docs_dir'],
-                    config['site_dir'],
-                    config['use_directory_urls']),
-                config)
+                title,
+                File(
+                    filename, config['docs_dir'], config['site_dir'], config['use_directory_urls']
+                ),
+                config,
+            )
             test_page.content = """
                 <h1 id="heading-1">Heading 1</h1>
                 <p>Content 1</p>
@@ -433,29 +440,40 @@ class SearchIndexTests(unittest.TestCase):
                 <p>Content 2</p>
                 <h3 id="heading-3">Heading 3</h1>
                 <p>Content 3</p>"""
-            test_page.markdown = dedent("""
+            test_page.markdown = dedent(
+                """
                 # Heading 1
                 ## Heading 2
-                ### Heading 3""")
+                ### Heading 3"""
+            )
             test_page.toc = get_toc(get_markdown_toc(test_page.markdown))
             return test_page
 
         validate = {
-            'full': (lambda data:
-                     self.assertEqual(len(data[0]), 4) and
-                     self.assertTrue([x for x in data[0][0] if x['title'] and x['text']])),
-            'sections': (lambda data:
-                         # Sanity
-                         self.assertEqual(len(data[0]), 4) and
-                         # Page
-                         (self.assertEqual(data[0][0]['title'], data[1].title) and
-                             self.assertTrue(data[0][0]['text'])) and
-                         # Headings
-                         self.assertTrue([x for x in data[0][1:] if x['title'] and not x['text']])),
-            'titles': (lambda data:
-                       # Sanity
-                       self.assertEqual(len(data[0]), 1) and
-                       self.assertFalse([x for x in data[0] if x['text']]))
+            'full': (
+                lambda data: self.assertEqual(len(data[0]), 4)
+                and self.assertTrue([x for x in data[0][0] if x['title'] and x['text']])
+            ),
+            'sections': (
+                lambda data:
+                # Sanity
+                self.assertEqual(len(data[0]), 4)
+                and
+                # Page
+                (
+                    self.assertEqual(data[0][0]['title'], data[1].title)
+                    and self.assertTrue(data[0][0]['text'])
+                )
+                and
+                # Headings
+                self.assertTrue([x for x in data[0][1:] if x['title'] and not x['text']])
+            ),
+            'titles': (
+                lambda data:
+                # Sanity
+                self.assertEqual(len(data[0]), 1)
+                and self.assertFalse([x for x in data[0] if x['text']])
+            ),
         }
 
         for option in ['full', 'sections', 'titles']:
@@ -471,7 +489,7 @@ class SearchIndexTests(unittest.TestCase):
 
             pages = [
                 test_page('Home', 'index.md', base_cfg),
-                test_page('About', 'about.md', base_cfg)
+                test_page('About', 'about.md', base_cfg),
             ]
 
             for page in pages:
@@ -492,7 +510,7 @@ class SearchIndexTests(unittest.TestCase):
         expected = {
             'docs': [],
             'config': {'prebuild_index': True},
-            'index': {'mock': 'index'}
+            'index': {'mock': 'index'},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_popen.call_count, 1)
@@ -510,7 +528,7 @@ class SearchIndexTests(unittest.TestCase):
         index = search_index.SearchIndex(prebuild_index=True)
         expected = {
             'docs': [],
-            'config': {'prebuild_index': True}
+            'config': {'prebuild_index': True},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_popen.call_count, 1)
@@ -528,7 +546,7 @@ class SearchIndexTests(unittest.TestCase):
         index = search_index.SearchIndex(prebuild_index=True)
         expected = {
             'docs': [],
-            'config': {'prebuild_index': True}
+            'config': {'prebuild_index': True},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_popen.call_count, 1)
@@ -546,7 +564,7 @@ class SearchIndexTests(unittest.TestCase):
         index = search_index.SearchIndex(prebuild_index=True)
         expected = {
             'docs': [],
-            'config': {'prebuild_index': True}
+            'config': {'prebuild_index': True},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_popen.call_count, 1)
@@ -564,7 +582,7 @@ class SearchIndexTests(unittest.TestCase):
         index = search_index.SearchIndex(prebuild_index=False)
         expected = {
             'docs': [],
-            'config': {'prebuild_index': False}
+            'config': {'prebuild_index': False},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_popen.call_count, 0)
@@ -579,7 +597,7 @@ class SearchIndexTests(unittest.TestCase):
         expected = {
             'docs': [],
             'config': {'prebuild_index': 'python', 'lang': 'en'},
-            'index': {'mock': 'index'}
+            'index': {'mock': 'index'},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_lunr.call_count, 1)
@@ -591,7 +609,7 @@ class SearchIndexTests(unittest.TestCase):
         index = search_index.SearchIndex(prebuild_index='python', lang='en')
         expected = {
             'docs': [],
-            'config': {'prebuild_index': 'python', 'lang': 'en'}
+            'config': {'prebuild_index': 'python', 'lang': 'en'},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(result, expected)
@@ -608,7 +626,7 @@ class SearchIndexTests(unittest.TestCase):
         expected = {
             'docs': [],
             'config': {'prebuild_index': 'node'},
-            'index': {'mock': 'index'}
+            'index': {'mock': 'index'},
         }
         result = json.loads(index.generate_search_index())
         self.assertEqual(mock_popen.call_count, 1)
diff --git a/mkdocs/tests/structure/file_tests.py b/mkdocs/tests/structure/file_tests.py
index d3d3cfad..b3076007 100644
--- a/mkdocs/tests/structure/file_tests.py
+++ b/mkdocs/tests/structure/file_tests.py
@@ -7,49 +7,56 @@ from mkdocs.tests.base import load_config, tempdir, PathAssertionMixin
 
 
 class TestFiles(PathAssertionMixin, unittest.TestCase):
-
     def test_file_eq(self):
         file = File('a.md', '/path/to/docs', '/path/to/site', use_directory_urls=False)
-        self.assertTrue(file == File('a.md', '/path/to/docs', '/path/to/site', use_directory_urls=False))
+        self.assertTrue(
+            file == File('a.md', '/path/to/docs', '/path/to/site', use_directory_urls=False)
+        )
 
     def test_file_ne(self):
         file = File('a.md', '/path/to/docs', '/path/to/site', use_directory_urls=False)
         # Different filename
-        self.assertTrue(file != File('b.md', '/path/to/docs', '/path/to/site', use_directory_urls=False))
+        self.assertTrue(
+            file != File('b.md', '/path/to/docs', '/path/to/site', use_directory_urls=False)
+        )
         # Different src_path
-        self.assertTrue(file != File('a.md', '/path/to/other', '/path/to/site', use_directory_urls=False))
+        self.assertTrue(
+            file != File('a.md', '/path/to/other', '/path/to/site', use_directory_urls=False)
+        )
         # Different URL
-        self.assertTrue(file != File('a.md', '/path/to/docs', '/path/to/site', use_directory_urls=True))
+        self.assertTrue(
+            file != File('a.md', '/path/to/docs', '/path/to/site', use_directory_urls=True)
+        )
 
     def test_sort_files(self):
         self.assertEqual(
             _sort_files(['b.md', 'bb.md', 'a.md', 'index.md', 'aa.md']),
-            ['index.md', 'a.md', 'aa.md', 'b.md', 'bb.md']
+            ['index.md', 'a.md', 'aa.md', 'b.md', 'bb.md'],
         )
 
         self.assertEqual(
             _sort_files(['b.md', 'index.html', 'a.md', 'index.md']),
-            ['index.html', 'index.md', 'a.md', 'b.md']
+            ['index.html', 'index.md', 'a.md', 'b.md'],
         )
 
         self.assertEqual(
             _sort_files(['a.md', 'index.md', 'b.md', 'index.html']),
-            ['index.md', 'index.html', 'a.md', 'b.md']
+            ['index.md', 'index.html', 'a.md', 'b.md'],
         )
 
         self.assertEqual(
             _sort_files(['.md', '_.md', 'a.md', 'index.md', '1.md']),
-            ['index.md', '.md', '1.md', '_.md', 'a.md']
+            ['index.md', '.md', '1.md', '_.md', 'a.md'],
         )
 
         self.assertEqual(
             _sort_files(['a.md', 'b.md', 'a.md']),
-            ['a.md', 'a.md', 'b.md']
+            ['a.md', 'a.md', 'b.md'],
         )
 
         self.assertEqual(
             _sort_files(['A.md', 'B.md', 'README.md']),
-            ['README.md', 'A.md', 'B.md']
+            ['README.md', 'A.md', 'B.md'],
         )
 
     def test_md_file(self):
@@ -320,7 +327,7 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             File('foo/bar.html', '/path/to/docs', '/path/to/site', use_directory_urls=True),
             File('foo/bar.jpg', '/path/to/docs', '/path/to/site', use_directory_urls=True),
             File('foo/bar.js', '/path/to/docs', '/path/to/site', use_directory_urls=True),
-            File('foo/bar.css', '/path/to/docs', '/path/to/site', use_directory_urls=True)
+            File('foo/bar.css', '/path/to/docs', '/path/to/site', use_directory_urls=True),
         ]
         files = Files(fs)
         self.assertEqual([f for f in files], fs)
@@ -342,38 +349,42 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
         self.assertTrue(extra_file.src_path in files)
         self.assertEqual(files.documentation_pages(), [fs[0], fs[1], extra_file])
 
-    @tempdir(files=[
-        'favicon.ico',
-        'index.md'
-    ])
-    @tempdir(files=[
-        'base.html',
-        'favicon.ico',
-        'style.css',
-        'foo.md',
-        'README',
-        '.ignore.txt',
-        '.ignore/file.txt',
-        'foo/.ignore.txt',
-        'foo/.ignore/file.txt'
-    ])
+    @tempdir(
+        files=[
+            'favicon.ico',
+            'index.md',
+        ]
+    )
+    @tempdir(
+        files=[
+            'base.html',
+            'favicon.ico',
+            'style.css',
+            'foo.md',
+            'README',
+            '.ignore.txt',
+            '.ignore/file.txt',
+            'foo/.ignore.txt',
+            'foo/.ignore/file.txt',
+        ]
+    )
     def test_add_files_from_theme(self, tdir, ddir):
         config = load_config(docs_dir=ddir, theme={'name': None, 'custom_dir': tdir})
         env = config['theme'].get_env()
         files = get_files(config)
         self.assertEqual(
             [file.src_path for file in files],
-            ['index.md', 'favicon.ico']
+            ['index.md', 'favicon.ico'],
         )
         files.add_files_from_theme(env, config)
         self.assertEqual(
             [file.src_path for file in files],
-            ['index.md', 'favicon.ico', 'style.css']
+            ['index.md', 'favicon.ico', 'style.css'],
         )
         # Ensure theme file does not override docs_dir file
         self.assertEqual(
             files.get_file_from_path('favicon.ico').abs_src_path,
-            os.path.normpath(os.path.join(ddir, 'favicon.ico'))
+            os.path.normpath(os.path.join(ddir, 'favicon.ico')),
         )
 
     def test_filter_paths(self):
@@ -412,7 +423,7 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             'foo/bar/baz/index.md',
             'foo.md',
             'foo/bar.md',
-            'foo/bar/baz.md'
+            'foo/bar/baz.md',
         ]
 
         to_file_urls = [
@@ -422,18 +433,18 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             'foo/bar/baz/',
             'foo/',
             'foo/bar/',
-            'foo/bar/baz/'
+            'foo/bar/baz/',
         ]
 
         from_file = File('img.jpg', '/path/to/docs', '/path/to/site', use_directory_urls=True)
         expected = [
-            'img.jpg',           # img.jpg relative to .
-            '../img.jpg',        # img.jpg relative to foo/
-            '../../img.jpg',     # img.jpg relative to foo/bar/
+            'img.jpg',  # img.jpg relative to .
+            '../img.jpg',  # img.jpg relative to foo/
+            '../../img.jpg',  # img.jpg relative to foo/bar/
             '../../../img.jpg',  # img.jpg relative to foo/bar/baz/
-            '../img.jpg',        # img.jpg relative to foo
-            '../../img.jpg',     # img.jpg relative to foo/bar
-            '../../../img.jpg'   # img.jpg relative to foo/bar/baz
+            '../img.jpg',  # img.jpg relative to foo
+            '../../img.jpg',  # img.jpg relative to foo/bar
+            '../../../img.jpg',  # img.jpg relative to foo/bar/baz
         ]
 
         for i, filename in enumerate(to_files):
@@ -445,13 +456,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
 
         from_file = File('foo/img.jpg', '/path/to/docs', '/path/to/site', use_directory_urls=True)
         expected = [
-            'foo/img.jpg',    # foo/img.jpg relative to .
-            'img.jpg',        # foo/img.jpg relative to foo/
-            '../img.jpg',     # foo/img.jpg relative to foo/bar/
+            'foo/img.jpg',  # foo/img.jpg relative to .
+            'img.jpg',  # foo/img.jpg relative to foo/
+            '../img.jpg',  # foo/img.jpg relative to foo/bar/
             '../../img.jpg',  # foo/img.jpg relative to foo/bar/baz/
-            'img.jpg',        # foo/img.jpg relative to foo
-            '../img.jpg',     # foo/img.jpg relative to foo/bar
-            '../../img.jpg'   # foo/img.jpg relative to foo/bar/baz
+            'img.jpg',  # foo/img.jpg relative to foo
+            '../img.jpg',  # foo/img.jpg relative to foo/bar
+            '../../img.jpg',  # foo/img.jpg relative to foo/bar/baz
         ]
 
         for i, filename in enumerate(to_files):
@@ -463,13 +474,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
 
         from_file = File('index.html', '/path/to/docs', '/path/to/site', use_directory_urls=True)
         expected = [
-            '.',         # . relative to .
-            '..',        # . relative to foo/
-            '../..',     # . relative to foo/bar/
+            '.',  # . relative to .
+            '..',  # . relative to foo/
+            '../..',  # . relative to foo/bar/
             '../../..',  # . relative to foo/bar/baz/
-            '..',        # . relative to foo
-            '../..',     # . relative to foo/bar
-            '../../..'   # . relative to foo/bar/baz
+            '..',  # . relative to foo
+            '../..',  # . relative to foo/bar
+            '../../..',  # . relative to foo/bar/baz
         ]
 
         for i, filename in enumerate(to_files):
@@ -481,13 +492,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
 
         from_file = File('file.md', '/path/to/docs', '/path/to/site', use_directory_urls=True)
         expected = [
-            'file/',           # file relative to .
-            '../file/',        # file relative to foo/
-            '../../file/',     # file relative to foo/bar/
+            'file/',  # file relative to .
+            '../file/',  # file relative to foo/
+            '../../file/',  # file relative to foo/bar/
             '../../../file/',  # file relative to foo/bar/baz/
-            '../file/',        # file relative to foo
-            '../../file/',     # file relative to foo/bar
-            '../../../file/'   # file relative to foo/bar/baz
+            '../file/',  # file relative to foo
+            '../../file/',  # file relative to foo/bar
+            '../../../file/',  # file relative to foo/bar/baz
         ]
 
         for i, filename in enumerate(to_files):
@@ -505,7 +516,7 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             'foo/bar/baz/index.md',
             'foo.md',
             'foo/bar.md',
-            'foo/bar/baz.md'
+            'foo/bar/baz.md',
         ]
 
         to_file_urls = [
@@ -515,18 +526,18 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             'foo/bar/baz/index.html',
             'foo.html',
             'foo/bar.html',
-            'foo/bar/baz.html'
+            'foo/bar/baz.html',
         ]
 
         from_file = File('img.jpg', '/path/to/docs', '/path/to/site', use_directory_urls=False)
         expected = [
-            'img.jpg',           # img.jpg relative to .
-            '../img.jpg',        # img.jpg relative to foo/
-            '../../img.jpg',     # img.jpg relative to foo/bar/
+            'img.jpg',  # img.jpg relative to .
+            '../img.jpg',  # img.jpg relative to foo/
+            '../../img.jpg',  # img.jpg relative to foo/bar/
             '../../../img.jpg',  # img.jpg relative to foo/bar/baz/
-            'img.jpg',           # img.jpg relative to foo.html
-            '../img.jpg',        # img.jpg relative to foo/bar.html
-            '../../img.jpg'      # img.jpg relative to foo/bar/baz.html
+            'img.jpg',  # img.jpg relative to foo.html
+            '../img.jpg',  # img.jpg relative to foo/bar.html
+            '../../img.jpg',  # img.jpg relative to foo/bar/baz.html
         ]
 
         for i, filename in enumerate(to_files):
@@ -538,13 +549,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
 
         from_file = File('foo/img.jpg', '/path/to/docs', '/path/to/site', use_directory_urls=False)
         expected = [
-            'foo/img.jpg',    # foo/img.jpg relative to .
-            'img.jpg',        # foo/img.jpg relative to foo/
-            '../img.jpg',     # foo/img.jpg relative to foo/bar/
+            'foo/img.jpg',  # foo/img.jpg relative to .
+            'img.jpg',  # foo/img.jpg relative to foo/
+            '../img.jpg',  # foo/img.jpg relative to foo/bar/
             '../../img.jpg',  # foo/img.jpg relative to foo/bar/baz/
-            'foo/img.jpg',    # foo/img.jpg relative to foo.html
-            'img.jpg',        # foo/img.jpg relative to foo/bar.html
-            '../img.jpg'      # foo/img.jpg relative to foo/bar/baz.html
+            'foo/img.jpg',  # foo/img.jpg relative to foo.html
+            'img.jpg',  # foo/img.jpg relative to foo/bar.html
+            '../img.jpg',  # foo/img.jpg relative to foo/bar/baz.html
         ]
 
         for i, filename in enumerate(to_files):
@@ -556,13 +567,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
 
         from_file = File('index.html', '/path/to/docs', '/path/to/site', use_directory_urls=False)
         expected = [
-            'index.html',           # index.html relative to .
-            '../index.html',        # index.html relative to foo/
-            '../../index.html',     # index.html relative to foo/bar/
+            'index.html',  # index.html relative to .
+            '../index.html',  # index.html relative to foo/
+            '../../index.html',  # index.html relative to foo/bar/
             '../../../index.html',  # index.html relative to foo/bar/baz/
-            'index.html',           # index.html relative to foo.html
-            '../index.html',        # index.html relative to foo/bar.html
-            '../../index.html'      # index.html relative to foo/bar/baz.html
+            'index.html',  # index.html relative to foo.html
+            '../index.html',  # index.html relative to foo/bar.html
+            '../../index.html',  # index.html relative to foo/bar/baz.html
         ]
 
         for i, filename in enumerate(to_files):
@@ -574,13 +585,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
 
         from_file = File('file.html', '/path/to/docs', '/path/to/site', use_directory_urls=False)
         expected = [
-            'file.html',           # file.html relative to .
-            '../file.html',        # file.html relative to foo/
-            '../../file.html',     # file.html relative to foo/bar/
+            'file.html',  # file.html relative to .
+            '../file.html',  # file.html relative to foo/
+            '../../file.html',  # file.html relative to foo/bar/
             '../../../file.html',  # file.html relative to foo/bar/baz/
-            'file.html',           # file.html relative to foo.html
-            '../file.html',        # file.html relative to foo/bar.html
-            '../../file.html'      # file.html relative to foo/bar/baz.html
+            'file.html',  # file.html relative to foo.html
+            '../file.html',  # file.html relative to foo/bar.html
+            '../../file.html',  # file.html relative to foo/bar/baz.html
         ]
 
         for i, filename in enumerate(to_files):
@@ -590,17 +601,19 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             self.assertEqual(from_file.url_relative_to(file.url), expected[i])
             self.assertEqual(from_file.url_relative_to(file), expected[i])
 
-    @tempdir(files=[
-        'index.md',
-        'readme.md',
-        'bar.css',
-        'bar.html',
-        'bar.jpg',
-        'bar.js',
-        'bar.md',
-        '.dotfile',
-        'templates/foo.html'
-    ])
+    @tempdir(
+        files=[
+            'index.md',
+            'readme.md',
+            'bar.css',
+            'bar.html',
+            'bar.jpg',
+            'bar.js',
+            'bar.md',
+            '.dotfile',
+            'templates/foo.html',
+        ]
+    )
     def test_get_files(self, tdir):
         config = load_config(docs_dir=tdir, extra_css=['bar.css'], extra_javascript=['bar.js'])
         files = get_files(config)
@@ -609,10 +622,12 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
         self.assertEqual(len(files), len(expected))
         self.assertEqual([f.src_path for f in files], expected)
 
-    @tempdir(files=[
-        'README.md',
-        'foo.md'
-    ])
+    @tempdir(
+        files=[
+            'README.md',
+            'foo.md',
+        ]
+    )
     def test_get_files_include_readme_without_index(self, tdir):
         config = load_config(docs_dir=tdir)
         files = get_files(config)
@@ -621,11 +636,13 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
         self.assertEqual(len(files), len(expected))
         self.assertEqual([f.src_path for f in files], expected)
 
-    @tempdir(files=[
-        'index.md',
-        'README.md',
-        'foo.md'
-    ])
+    @tempdir(
+        files=[
+            'index.md',
+            'README.md',
+            'foo.md',
+        ]
+    )
     def test_get_files_exclude_readme_with_index(self, tdir):
         config = load_config(docs_dir=tdir)
         files = get_files(config)
@@ -683,7 +700,7 @@ class TestFiles(PathAssertionMixin, unittest.TestCase):
             File('foo/bar.html', '/path/to/docs', '/path/to/site', use_directory_urls=True),
             File('foo/bar.jpg', '/path/to/docs', '/path/to/site', use_directory_urls=True),
             File('foo/bar.js', '/path/to/docs', '/path/to/site', use_directory_urls=True),
-            File('foo/bar.css', '/path/to/docs', '/path/to/site', use_directory_urls=True)
+            File('foo/bar.css', '/path/to/docs', '/path/to/site', use_directory_urls=True),
         ]
         files = Files(fs)
         self.assertEqual(len(files), 6)
diff --git a/mkdocs/tests/structure/nav_tests.py b/mkdocs/tests/structure/nav_tests.py
index 81849236..de9141ea 100644
--- a/mkdocs/tests/structure/nav_tests.py
+++ b/mkdocs/tests/structure/nav_tests.py
@@ -16,17 +16,22 @@ class SiteNavigationTests(unittest.TestCase):
     def test_simple_nav(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'About': 'about.md'}
+            {'About': 'about.md'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/')
-        Page(title='About', url='/about/')
-        """)
-        cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files(
-            [File(list(item.values())[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-             for item in nav_cfg]
+        expected = dedent(
+            """
+            Page(title='Home', url='/')
+            Page(title='About', url='/about/')
+            """
         )
+        cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
+        fs = [
+            File(
+                list(item.values())[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']
+            )
+            for item in nav_cfg
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 2)
@@ -36,17 +41,22 @@ class SiteNavigationTests(unittest.TestCase):
     def test_nav_no_directory_urls(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'About': 'about.md'}
+            {'About': 'about.md'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/index.html')
-        Page(title='About', url='/about.html')
-        """)
-        cfg = load_config(nav=nav_cfg, use_directory_urls=False, site_url='http://example.com/')
-        files = Files(
-            [File(list(item.values())[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-             for item in nav_cfg]
+        expected = dedent(
+            """
+            Page(title='Home', url='/index.html')
+            Page(title='About', url='/about.html')
+            """
         )
+        cfg = load_config(nav=nav_cfg, use_directory_urls=False, site_url='http://example.com/')
+        fs = [
+            File(
+                list(item.values())[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']
+            )
+            for item in nav_cfg
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 2)
@@ -55,16 +65,19 @@ class SiteNavigationTests(unittest.TestCase):
 
     def test_nav_missing_page(self):
         nav_cfg = [
-            {'Home': 'index.md'}
+            {'Home': 'index.md'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/')
-        """)
+        expected = dedent(
+            """
+            Page(title='Home', url='/')
+            """
+        )
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('page_not_in_nav.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File('page_not_in_nav.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 1)
@@ -75,17 +88,20 @@ class SiteNavigationTests(unittest.TestCase):
     def test_nav_no_title(self):
         nav_cfg = [
             'index.md',
-            {'About': 'about.md'}
+            {'About': 'about.md'},
         ]
-        expected = dedent("""
-        Page(title=[blank], url='/')
-        Page(title='About', url='/about/')
-        """)
+        expected = dedent(
+            """
+            Page(title=[blank], url='/')
+            Page(title='About', url='/about/')
+            """
+        )
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([
+        fs = [
             File(nav_cfg[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File(nav_cfg[1]['About'], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File(nav_cfg[1]['About'], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 2)
@@ -95,15 +111,18 @@ class SiteNavigationTests(unittest.TestCase):
         nav_cfg = [
             {'Home': 'index.md'},
             {'Local': '/local.html'},
-            {'External': 'http://example.com/external.html'}
+            {'External': 'http://example.com/external.html'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/')
-        Link(title='Local', url='/local.html')
-        Link(title='External', url='http://example.com/external.html')
-        """)
+        expected = dedent(
+            """
+            Page(title='Home', url='/')
+            Link(title='Local', url='/local.html')
+            Link(title='External', url='http://example.com/external.html')
+            """
+        )
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         with self.assertLogs('mkdocs', level='DEBUG') as cm:
             site_navigation = get_navigation(files, cfg)
         self.assertEqual(
@@ -112,8 +131,8 @@ class SiteNavigationTests(unittest.TestCase):
                 "DEBUG:mkdocs.structure.nav:An absolute path to '/local.html' is included in the "
                 "'nav' configuration, which presumably points to an external resource.",
                 "DEBUG:mkdocs.structure.nav:An external link to 'http://example.com/external.html' "
-                "is included in the 'nav' configuration."
-            ]
+                "is included in the 'nav' configuration.",
+            ],
         )
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 3)
@@ -123,15 +142,18 @@ class SiteNavigationTests(unittest.TestCase):
         nav_cfg = [
             {'Home': 'index.md'},
             {'Missing': 'missing.html'},
-            {'Bad External': 'example.com'}
+            {'Bad External': 'example.com'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/')
-        Link(title='Missing', url='missing.html')
-        Link(title='Bad External', url='example.com')
-        """)
+        expected = dedent(
+            """
+            Page(title='Home', url='/')
+            Link(title='Missing', url='missing.html')
+            Link(title='Bad External', url='example.com')
+            """
+        )
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])])
+        fs = [File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         with self.assertLogs('mkdocs', level='WARNING') as cm:
             site_navigation = get_navigation(files, cfg)
         self.assertEqual(
@@ -140,8 +162,8 @@ class SiteNavigationTests(unittest.TestCase):
                 "WARNING:mkdocs.structure.nav:A relative path to 'missing.html' is included "
                 "in the 'nav' configuration, which is not found in the documentation files",
                 "WARNING:mkdocs.structure.nav:A relative path to 'example.com' is included "
-                "in the 'nav' configuration, which is not found in the documentation files"
-            ]
+                "in the 'nav' configuration, which is not found in the documentation files",
+            ],
         )
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 3)
@@ -150,42 +172,53 @@ class SiteNavigationTests(unittest.TestCase):
     def test_indented_nav(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'API Guide': [
-                {'Running': 'api-guide/running.md'},
-                {'Testing': 'api-guide/testing.md'},
-                {'Debugging': 'api-guide/debugging.md'},
-                {'Advanced': [
-                    {'Part 1': 'api-guide/advanced/part-1.md'},
-                ]},
-            ]},
-            {'About': [
-                {'Release notes': 'about/release-notes.md'},
-                {'License': '/license.html'}
-            ]},
-            {'External': 'https://example.com/'}
+            {
+                'API Guide': [
+                    {'Running': 'api-guide/running.md'},
+                    {'Testing': 'api-guide/testing.md'},
+                    {'Debugging': 'api-guide/debugging.md'},
+                    {
+                        'Advanced': [
+                            {'Part 1': 'api-guide/advanced/part-1.md'},
+                        ]
+                    },
+                ]
+            },
+            {
+                'About': [
+                    {'Release notes': 'about/release-notes.md'},
+                    {'License': '/license.html'},
+                ]
+            },
+            {'External': 'https://example.com/'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/')
-        Section(title='API Guide')
-            Page(title='Running', url='/api-guide/running/')
-            Page(title='Testing', url='/api-guide/testing/')
-            Page(title='Debugging', url='/api-guide/debugging/')
-            Section(title='Advanced')
-                Page(title='Part 1', url='/api-guide/advanced/part-1/')
-        Section(title='About')
-            Page(title='Release notes', url='/about/release-notes/')
-            Link(title='License', url='/license.html')
-        Link(title='External', url='https://example.com/')
-        """)
+        expected = dedent(
+            """
+            Page(title='Home', url='/')
+            Section(title='API Guide')
+                Page(title='Running', url='/api-guide/running/')
+                Page(title='Testing', url='/api-guide/testing/')
+                Page(title='Debugging', url='/api-guide/debugging/')
+                Section(title='Advanced')
+                    Page(title='Part 1', url='/api-guide/advanced/part-1/')
+            Section(title='About')
+                Page(title='Release notes', url='/about/release-notes/')
+                Link(title='License', url='/license.html')
+            Link(title='External', url='https://example.com/')
+            """
+        )
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([
-            File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/running.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/testing.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/debugging.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/advanced/part-1.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('about/release-notes.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        fs = [
+            'index.md',
+            'api-guide/running.md',
+            'api-guide/testing.md',
+            'api-guide/debugging.md',
+            'api-guide/advanced/part-1.md',
+            'about/release-notes.md',
+        ]
+        files = Files(
+            [File(s, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']) for s in fs]
+        )
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 4)
@@ -196,23 +229,40 @@ class SiteNavigationTests(unittest.TestCase):
         self.assertIsNone(site_navigation.items[1].parent)
         self.assertEqual(site_navigation.items[1].ancestors, [])
         self.assertEqual(len(site_navigation.items[1].children), 4)
-        self.assertEqual(repr(site_navigation.items[1].children[0].parent), "Section(title='API Guide')")
+        self.assertEqual(
+            repr(site_navigation.items[1].children[0].parent), "Section(title='API Guide')"
+        )
         self.assertEqual(site_navigation.items[1].children[0].ancestors, [site_navigation.items[1]])
-        self.assertEqual(repr(site_navigation.items[1].children[1].parent), "Section(title='API Guide')")
+        self.assertEqual(
+            repr(site_navigation.items[1].children[1].parent), "Section(title='API Guide')"
+        )
         self.assertEqual(site_navigation.items[1].children[1].ancestors, [site_navigation.items[1]])
-        self.assertEqual(repr(site_navigation.items[1].children[2].parent), "Section(title='API Guide')")
+        self.assertEqual(
+            repr(site_navigation.items[1].children[2].parent), "Section(title='API Guide')"
+        )
         self.assertEqual(site_navigation.items[1].children[2].ancestors, [site_navigation.items[1]])
-        self.assertEqual(repr(site_navigation.items[1].children[3].parent), "Section(title='API Guide')")
+        self.assertEqual(
+            repr(site_navigation.items[1].children[3].parent), "Section(title='API Guide')"
+        )
         self.assertEqual(site_navigation.items[1].children[3].ancestors, [site_navigation.items[1]])
         self.assertEqual(len(site_navigation.items[1].children[3].children), 1)
-        self.assertEqual(repr(site_navigation.items[1].children[3].children[0].parent), "Section(title='Advanced')")
-        self.assertEqual(site_navigation.items[1].children[3].children[0].ancestors,
-                         [site_navigation.items[1].children[3], site_navigation.items[1]])
+        self.assertEqual(
+            repr(site_navigation.items[1].children[3].children[0].parent),
+            "Section(title='Advanced')",
+        )
+        self.assertEqual(
+            site_navigation.items[1].children[3].children[0].ancestors,
+            [site_navigation.items[1].children[3], site_navigation.items[1]],
+        )
         self.assertIsNone(site_navigation.items[2].parent)
         self.assertEqual(len(site_navigation.items[2].children), 2)
-        self.assertEqual(repr(site_navigation.items[2].children[0].parent), "Section(title='About')")
+        self.assertEqual(
+            repr(site_navigation.items[2].children[0].parent), "Section(title='About')"
+        )
         self.assertEqual(site_navigation.items[2].children[0].ancestors, [site_navigation.items[2]])
-        self.assertEqual(repr(site_navigation.items[2].children[1].parent), "Section(title='About')")
+        self.assertEqual(
+            repr(site_navigation.items[2].children[1].parent), "Section(title='About')"
+        )
         self.assertEqual(site_navigation.items[2].children[1].ancestors, [site_navigation.items[2]])
         self.assertIsNone(site_navigation.items[3].parent)
         self.assertEqual(site_navigation.items[3].ancestors, [])
@@ -224,16 +274,21 @@ class SiteNavigationTests(unittest.TestCase):
             {'Contact': 'about/contact.md'},
             {'License Title': 'about/sub/license.md'},
         ]
-        expected = dedent("""
-        Page(title='Home', url='/')
-        Page(title='Contact', url='/about/contact/')
-        Page(title='License Title', url='/about/sub/license/')
-        """)
-        cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files(
-            [File(list(item.values())[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-             for item in nav_cfg]
+        expected = dedent(
+            """
+            Page(title='Home', url='/')
+            Page(title='Contact', url='/about/contact/')
+            Page(title='License Title', url='/about/sub/license/')
+            """
         )
+        cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
+        fs = [
+            File(
+                list(item.values())[0], cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']
+            )
+            for item in nav_cfg
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 3)
@@ -243,18 +298,22 @@ class SiteNavigationTests(unittest.TestCase):
         nav_cfg = [
             'index.md',
             'about/contact.md',
-            'about/sub/license.md'
+            'about/sub/license.md',
         ]
-        expected = dedent("""
-        Page(title=[blank], url='/')
-        Page(title=[blank], url='/about/contact/')
-        Page(title=[blank], url='/about/sub/license/')
-        """)
+        expected = dedent(
+            """
+            Page(title=[blank], url='/')
+            Page(title=[blank], url='/about/contact/')
+            Page(title=[blank], url='/about/sub/license/')
+            """
+        )
 
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files(
-            [File(item, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']) for item in nav_cfg]
-        )
+        fs = [
+            File(item, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
+            for item in nav_cfg
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 3)
@@ -268,31 +327,38 @@ class SiteNavigationTests(unittest.TestCase):
             'about\\contact.md',
             'about\\sub\\license.md',
         ]
-        expected = dedent("""
-        Page(title=[blank], url='/')
-        Page(title=[blank], url='/about/contact/')
-        Page(title=[blank], url='/about/sub/license/')
-        """)
+        expected = dedent(
+            """
+            Page(title=[blank], url='/')
+            Page(title=[blank], url='/about/contact/')
+            Page(title=[blank], url='/about/sub/license/')
+            """
+        )
 
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files(
-            [File(item, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']) for item in nav_cfg]
-        )
+        fs = [
+            File(item, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
+            for item in nav_cfg
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 3)
         self.assertEqual(len(site_navigation.pages), 3)
 
     def test_nav_from_files(self):
-        expected = dedent("""
-        Page(title=[blank], url='/')
-        Page(title=[blank], url='/about/')
-        """)
+        expected = dedent(
+            """
+            Page(title=[blank], url='/')
+            Page(title=[blank], url='/about/')
+            """
+        )
         cfg = load_config(site_url='http://example.com/')
-        files = Files([
+        fs = [
             File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('about.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+            File('about.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+        ]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 2)
@@ -300,28 +366,33 @@ class SiteNavigationTests(unittest.TestCase):
         self.assertEqual(repr(site_navigation.homepage), "Page(title=[blank], url='/')")
 
     def test_nav_from_nested_files(self):
-        expected = dedent("""
-        Page(title=[blank], url='/')
-        Section(title='About')
-            Page(title=[blank], url='/about/license/')
-            Page(title=[blank], url='/about/release-notes/')
-        Section(title='Api guide')
-            Page(title=[blank], url='/api-guide/debugging/')
-            Page(title=[blank], url='/api-guide/running/')
-            Page(title=[blank], url='/api-guide/testing/')
-            Section(title='Advanced')
-                Page(title=[blank], url='/api-guide/advanced/part-1/')
-        """)
+        expected = dedent(
+            """
+            Page(title=[blank], url='/')
+            Section(title='About')
+                Page(title=[blank], url='/about/license/')
+                Page(title=[blank], url='/about/release-notes/')
+            Section(title='Api guide')
+                Page(title=[blank], url='/api-guide/debugging/')
+                Page(title=[blank], url='/api-guide/running/')
+                Page(title=[blank], url='/api-guide/testing/')
+                Section(title='Advanced')
+                    Page(title=[blank], url='/api-guide/advanced/part-1/')
+            """
+        )
         cfg = load_config(site_url='http://example.com/')
-        files = Files([
-            File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('about/license.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('about/release-notes.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/debugging.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/running.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/testing.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/advanced/part-1.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        fs = [
+            'index.md',
+            'about/license.md',
+            'about/release-notes.md',
+            'api-guide/debugging.md',
+            'api-guide/running.md',
+            'api-guide/testing.md',
+            'api-guide/advanced/part-1.md',
+        ]
+        files = Files(
+            [File(s, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']) for s in fs]
+        )
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(str(site_navigation).strip(), expected)
         self.assertEqual(len(site_navigation.items), 3)
@@ -331,29 +402,38 @@ class SiteNavigationTests(unittest.TestCase):
     def test_active(self):
         nav_cfg = [
             {'Home': 'index.md'},
-            {'API Guide': [
-                {'Running': 'api-guide/running.md'},
-                {'Testing': 'api-guide/testing.md'},
-                {'Debugging': 'api-guide/debugging.md'},
-                {'Advanced': [
-                    {'Part 1': 'api-guide/advanced/part-1.md'},
-                ]},
-            ]},
-            {'About': [
-                {'Release notes': 'about/release-notes.md'},
-                {'License': 'about/license.md'}
-            ]}
+            {
+                'API Guide': [
+                    {'Running': 'api-guide/running.md'},
+                    {'Testing': 'api-guide/testing.md'},
+                    {'Debugging': 'api-guide/debugging.md'},
+                    {
+                        'Advanced': [
+                            {'Part 1': 'api-guide/advanced/part-1.md'},
+                        ]
+                    },
+                ]
+            },
+            {
+                'About': [
+                    {'Release notes': 'about/release-notes.md'},
+                    {'License': 'about/license.md'},
+                ]
+            },
         ]
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([
-            File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/running.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/testing.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/debugging.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('api-guide/advanced/part-1.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('about/release-notes.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-            File('about/license.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
-        ])
+        fs = [
+            'index.md',
+            'api-guide/running.md',
+            'api-guide/testing.md',
+            'api-guide/debugging.md',
+            'api-guide/advanced/part-1.md',
+            'about/release-notes.md',
+            'about/license.md',
+        ]
+        files = Files(
+            [File(s, cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']) for s in fs]
+        )
         site_navigation = get_navigation(files, cfg)
         # Confirm nothing is active
         self.assertTrue(all(page.active is False for page in site_navigation.pages))
@@ -381,15 +461,18 @@ class SiteNavigationTests(unittest.TestCase):
 
     def test_get_by_type_nested_sections(self):
         nav_cfg = [
-            {'Section 1': [
-                {'Section 2': [
-                    {'Page': 'page.md'}
-                ]}
-            ]}
+            {
+                'Section 1': [
+                    {
+                        'Section 2': [
+                            {'Page': 'page.md'},
+                        ]
+                    },
+                ]
+            },
         ]
         cfg = load_config(nav=nav_cfg, site_url='http://example.com/')
-        files = Files([
-            File('page.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
-        ])
+        fs = [File('page.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])]
+        files = Files(fs)
         site_navigation = get_navigation(files, cfg)
         self.assertEqual(len(_get_by_type(site_navigation, Section)), 2)
diff --git a/mkdocs/tests/structure/page_tests.py b/mkdocs/tests/structure/page_tests.py
index 35c1886b..af666b11 100644
--- a/mkdocs/tests/structure/page_tests.py
+++ b/mkdocs/tests/structure/page_tests.py
@@ -11,7 +11,9 @@ from mkdocs.tests.base import load_config, dedent
 
 class PageTests(unittest.TestCase):
 
-    DOCS_DIR = os.path.join(os.path.abspath(os.path.dirname(__file__)), '../integration/subpages/docs')
+    DOCS_DIR = os.path.join(
+        os.path.abspath(os.path.dirname(__file__)), '../integration/subpages/docs'
+    )
 
     def test_homepage(self):
         cfg = load_config(docs_dir=self.DOCS_DIR)
@@ -429,52 +431,24 @@ class PageTests(unittest.TestCase):
 
     def test_page_edit_url(self):
         configs = [
+            {'repo_url': 'http://github.com/mkdocs/mkdocs'},
+            {'repo_url': 'https://github.com/mkdocs/mkdocs/'},
+            {'repo_url': 'http://example.com'},
+            {'repo_url': 'http://example.com', 'edit_uri': 'edit/master'},
+            {'repo_url': 'http://example.com', 'edit_uri': '/edit/master'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': '/edit/master/'},
+            {'repo_url': 'http://example.com/foo', 'edit_uri': '/edit/master/'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': '/edit/master'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': 'edit/master/'},
+            {'repo_url': 'http://example.com/foo', 'edit_uri': 'edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': '?query=edit/master'},
+            {'repo_url': 'http://example.com/', 'edit_uri': '?query=edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': '#edit/master'},
+            {'repo_url': 'http://example.com/', 'edit_uri': '#edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': ''},  # Set to blank value
             {
-                'repo_url': 'http://github.com/mkdocs/mkdocs'
-            },
-            {
-                'repo_url': 'https://github.com/mkdocs/mkdocs/'
-            }, {
-                'repo_url': 'http://example.com'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': 'edit/master'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '/edit/master'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': '/edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo',
-                'edit_uri': '/edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': '/edit/master'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': 'edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo',
-                'edit_uri': 'edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '?query=edit/master'
-            }, {
-                'repo_url': 'http://example.com/',
-                'edit_uri': '?query=edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '#edit/master'
-            }, {
-                'repo_url': 'http://example.com/',
-                'edit_uri': '#edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': ''  # Set to blank value
-            }, {
                 # Nothing defined
-            }
+            },
         ]
 
         expected = [
@@ -493,7 +467,7 @@ class PageTests(unittest.TestCase):
             'http://example.com#edit/master/testing.md',
             'http://example.com/#edit/master/testing.md',
             None,
-            None
+            None,
         ]
 
         for i, c in enumerate(configs):
@@ -505,47 +479,20 @@ class PageTests(unittest.TestCase):
 
     def test_nested_page_edit_url(self):
         configs = [
-            {
-                'repo_url': 'http://github.com/mkdocs/mkdocs'
-            },
-            {
-                'repo_url': 'https://github.com/mkdocs/mkdocs/'
-            }, {
-                'repo_url': 'http://example.com'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': 'edit/master'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '/edit/master'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': '/edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo',
-                'edit_uri': '/edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': '/edit/master'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': 'edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo',
-                'edit_uri': 'edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '?query=edit/master'
-            }, {
-                'repo_url': 'http://example.com/',
-                'edit_uri': '?query=edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '#edit/master'
-            }, {
-                'repo_url': 'http://example.com/',
-                'edit_uri': '#edit/master/'
-            }
+            {'repo_url': 'http://github.com/mkdocs/mkdocs'},
+            {'repo_url': 'https://github.com/mkdocs/mkdocs/'},
+            {'repo_url': 'http://example.com'},
+            {'repo_url': 'http://example.com', 'edit_uri': 'edit/master'},
+            {'repo_url': 'http://example.com', 'edit_uri': '/edit/master'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': '/edit/master/'},
+            {'repo_url': 'http://example.com/foo', 'edit_uri': '/edit/master/'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': '/edit/master'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': 'edit/master/'},
+            {'repo_url': 'http://example.com/foo', 'edit_uri': 'edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': '?query=edit/master'},
+            {'repo_url': 'http://example.com/', 'edit_uri': '?query=edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': '#edit/master'},
+            {'repo_url': 'http://example.com/', 'edit_uri': '#edit/master/'},
         ]
 
         expected = [
@@ -562,13 +509,15 @@ class PageTests(unittest.TestCase):
             'http://example.com?query=edit/master/sub1/non-index.md',
             'http://example.com/?query=edit/master/sub1/non-index.md',
             'http://example.com#edit/master/sub1/non-index.md',
-            'http://example.com/#edit/master/sub1/non-index.md'
+            'http://example.com/#edit/master/sub1/non-index.md',
         ]
 
         for i, c in enumerate(configs):
             c['docs_dir'] = self.DOCS_DIR
             cfg = load_config(**c)
-            fl = File('sub1/non-index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
+            fl = File(
+                'sub1/non-index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']
+            )
             pg = Page('Foo', fl, cfg)
             self.assertEqual(pg.url, 'sub1/non-index/')
             self.assertEqual(pg.edit_url, expected[i])
@@ -576,47 +525,20 @@ class PageTests(unittest.TestCase):
     @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
     def test_nested_page_edit_url_windows(self):
         configs = [
-            {
-                'repo_url': 'http://github.com/mkdocs/mkdocs'
-            },
-            {
-                'repo_url': 'https://github.com/mkdocs/mkdocs/'
-            }, {
-                'repo_url': 'http://example.com'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': 'edit/master'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '/edit/master'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': '/edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo',
-                'edit_uri': '/edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': '/edit/master'
-            }, {
-                'repo_url': 'http://example.com/foo/',
-                'edit_uri': 'edit/master/'
-            }, {
-                'repo_url': 'http://example.com/foo',
-                'edit_uri': 'edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '?query=edit/master'
-            }, {
-                'repo_url': 'http://example.com/',
-                'edit_uri': '?query=edit/master/'
-            }, {
-                'repo_url': 'http://example.com',
-                'edit_uri': '#edit/master'
-            }, {
-                'repo_url': 'http://example.com/',
-                'edit_uri': '#edit/master/'
-            }
+            {'repo_url': 'http://github.com/mkdocs/mkdocs'},
+            {'repo_url': 'https://github.com/mkdocs/mkdocs/'},
+            {'repo_url': 'http://example.com'},
+            {'repo_url': 'http://example.com', 'edit_uri': 'edit/master'},
+            {'repo_url': 'http://example.com', 'edit_uri': '/edit/master'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': '/edit/master/'},
+            {'repo_url': 'http://example.com/foo', 'edit_uri': '/edit/master/'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': '/edit/master'},
+            {'repo_url': 'http://example.com/foo/', 'edit_uri': 'edit/master/'},
+            {'repo_url': 'http://example.com/foo', 'edit_uri': 'edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': '?query=edit/master'},
+            {'repo_url': 'http://example.com/', 'edit_uri': '?query=edit/master/'},
+            {'repo_url': 'http://example.com', 'edit_uri': '#edit/master'},
+            {'repo_url': 'http://example.com/', 'edit_uri': '#edit/master/'},
         ]
 
         expected = [
@@ -633,13 +555,15 @@ class PageTests(unittest.TestCase):
             'http://example.com?query=edit/master/sub1/non-index.md',
             'http://example.com/?query=edit/master/sub1/non-index.md',
             'http://example.com#edit/master/sub1/non-index.md',
-            'http://example.com/#edit/master/sub1/non-index.md'
+            'http://example.com/#edit/master/sub1/non-index.md',
         ]
 
         for i, c in enumerate(configs):
             c['docs_dir'] = self.DOCS_DIR
             cfg = load_config(**c)
-            fl = File('sub1\\non-index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls'])
+            fl = File(
+                'sub1\\non-index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']
+            )
             pg = Page('Foo', fl, cfg)
             self.assertEqual(pg.url, 'sub1/non-index/')
             self.assertEqual(pg.edit_url, expected[i])
@@ -652,14 +576,19 @@ class PageTests(unittest.TestCase):
         self.assertEqual(pg.content, None)
         self.assertEqual(pg.toc, [])
         pg.render(cfg, [fl])
-        self.assertTrue(pg.content.startswith(
-            '<h1 id="welcome-to-mkdocs">Welcome to MkDocs</h1>\n'
-        ))
-        self.assertEqual(str(pg.toc).strip(), dedent("""
-            Welcome to MkDocs - #welcome-to-mkdocs
-                Commands - #commands
-                Project layout - #project-layout
-        """))
+        self.assertTrue(
+            pg.content.startswith('<h1 id="welcome-to-mkdocs">Welcome to MkDocs</h1>\n')
+        )
+        self.assertEqual(
+            str(pg.toc).strip(),
+            dedent(
+                """
+                Welcome to MkDocs - #welcome-to-mkdocs
+                    Commands - #commands
+                    Project layout - #project-layout
+                """
+            ),
+        )
 
     def test_missing_page(self):
         cfg = load_config()
@@ -670,7 +599,6 @@ class PageTests(unittest.TestCase):
 
 
 class SourceDateEpochTests(unittest.TestCase):
-
     def setUp(self):
         self.default = os.environ.get('SOURCE_DATE_EPOCH', None)
         os.environ['SOURCE_DATE_EPOCH'] = '0'
@@ -690,13 +618,18 @@ class SourceDateEpochTests(unittest.TestCase):
 
 class RelativePathExtensionTests(unittest.TestCase):
 
-    DOCS_DIR = os.path.join(os.path.abspath(os.path.dirname(__file__)), '../integration/subpages/docs')
+    DOCS_DIR = os.path.join(
+        os.path.abspath(os.path.dirname(__file__)), '../integration/subpages/docs'
+    )
 
     def get_rendered_result(self, files):
         cfg = load_config(docs_dir=self.DOCS_DIR)
-        fs = []
-        for f in files:
-            fs.append(File(f.replace('/', os.sep), cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']))
+        fs = [
+            File(
+                f.replace('/', os.sep), cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']
+            )
+            for f in files
+        ]
         pg = Page('Foo', fs[0], cfg)
         pg.read_source(cfg)
         pg.render(cfg, Files(fs))
@@ -706,105 +639,113 @@ class RelativePathExtensionTests(unittest.TestCase):
     def test_relative_html_link(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'non-index.md']),
-            '<p><a href="non-index/">link</a></p>'  # No trailing /
+            '<p><a href="non-index/">link</a></p>',  # No trailing /
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](index.md)'))
     def test_relative_html_link_index(self):
         self.assertEqual(
             self.get_rendered_result(['non-index.md', 'index.md']),
-            '<p><a href="..">link</a></p>'
+            '<p><a href="..">link</a></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/index.md)'))
     def test_relative_html_link_sub_index(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'sub2/index.md']),
-            '<p><a href="sub2/">link</a></p>'  # No trailing /
+            '<p><a href="sub2/">link</a></p>',  # No trailing /
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/non-index.md)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/non-index.md)')
+    )
     def test_relative_html_link_sub_page(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'sub2/non-index.md']),
-            '<p><a href="sub2/non-index/">link</a></p>'  # No trailing /
+            '<p><a href="sub2/non-index/">link</a></p>',  # No trailing /
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](file%20name.md)'))
     def test_relative_html_link_with_encoded_space(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'file name.md']),
-            '<p><a href="file%20name/">link</a></p>'
+            '<p><a href="file%20name/">link</a></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](file name.md)'))
     def test_relative_html_link_with_unencoded_space(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'file name.md']),
-            '<p><a href="file%20name/">link</a></p>'
+            '<p><a href="file%20name/">link</a></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](../index.md)'))
     def test_relative_html_link_parent_index(self):
         self.assertEqual(
             self.get_rendered_result(['sub2/non-index.md', 'index.md']),
-            '<p><a href="../..">link</a></p>'
+            '<p><a href="../..">link</a></p>',
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](non-index.md#hash)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open', mock.mock_open(read_data='[link](non-index.md#hash)')
+    )
     def test_relative_html_link_hash(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'non-index.md']),
-            '<p><a href="non-index/#hash">link</a></p>'
+            '<p><a href="non-index/#hash">link</a></p>',
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/index.md#hash)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/index.md#hash)')
+    )
     def test_relative_html_link_sub_index_hash(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'sub2/index.md']),
-            '<p><a href="sub2/#hash">link</a></p>'
+            '<p><a href="sub2/#hash">link</a></p>',
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/non-index.md#hash)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open', mock.mock_open(read_data='[link](sub2/non-index.md#hash)')
+    )
     def test_relative_html_link_sub_page_hash(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'sub2/non-index.md']),
-            '<p><a href="sub2/non-index/#hash">link</a></p>'
+            '<p><a href="sub2/non-index/#hash">link</a></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](#hash)'))
     def test_relative_html_link_hash_only(self):
         self.assertEqual(
             self.get_rendered_result(['index.md']),
-            '<p><a href="#hash">link</a></p>'
+            '<p><a href="#hash">link</a></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='![image](image.png)'))
     def test_relative_image_link_from_homepage(self):
         self.assertEqual(
             self.get_rendered_result(['index.md', 'image.png']),
-            '<p><img alt="image" src="image.png" /></p>'  # no opening ./
+            '<p><img alt="image" src="image.png" /></p>',  # no opening ./
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='![image](../image.png)'))
     def test_relative_image_link_from_subpage(self):
         self.assertEqual(
             self.get_rendered_result(['sub2/non-index.md', 'image.png']),
-            '<p><img alt="image" src="../../image.png" /></p>'
+            '<p><img alt="image" src="../../image.png" /></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='![image](image.png)'))
     def test_relative_image_link_from_sibling(self):
         self.assertEqual(
             self.get_rendered_result(['non-index.md', 'image.png']),
-            '<p><img alt="image" src="../image.png" /></p>'
+            '<p><img alt="image" src="../image.png" /></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='*__not__ a link*.'))
     def test_no_links(self):
         self.assertEqual(
             self.get_rendered_result(['index.md']),
-            '<p><em><strong>not</strong> a link</em>.</p>'
+            '<p><em><strong>not</strong> a link</em>.</p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[link](non-existent.md)'))
@@ -812,33 +753,43 @@ class RelativePathExtensionTests(unittest.TestCase):
         with self.assertLogs('mkdocs', level='WARNING') as cm:
             self.assertEqual(
                 self.get_rendered_result(['index.md']),
-                '<p><a href="non-existent.md">link</a></p>'
+                '<p><a href="non-existent.md">link</a></p>',
             )
         self.assertEqual(
             cm.output,
-            ["WARNING:mkdocs.structure.pages:Documentation file 'index.md' contains a link "
-             "to 'non-existent.md' which is not found in the documentation files."]
+            [
+                "WARNING:mkdocs.structure.pages:Documentation file 'index.md' contains a link "
+                "to 'non-existent.md' which is not found in the documentation files."
+            ],
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[external](http://example.com/index.md)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open',
+        mock.mock_open(read_data='[external](http://example.com/index.md)'),
+    )
     def test_external_link(self):
         self.assertEqual(
             self.get_rendered_result(['index.md']),
-            '<p><a href="http://example.com/index.md">external</a></p>'
+            '<p><a href="http://example.com/index.md">external</a></p>',
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[absolute link](/path/to/file.md)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open', mock.mock_open(read_data='[absolute link](/path/to/file.md)')
+    )
     def test_absolute_link(self):
         self.assertEqual(
             self.get_rendered_result(['index.md']),
-            '<p><a href="/path/to/file.md">absolute link</a></p>'
+            '<p><a href="/path/to/file.md">absolute link</a></p>',
         )
 
-    @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='[absolute local path](\\image.png)'))
+    @mock.patch(
+        'mkdocs.structure.pages.open',
+        mock.mock_open(read_data='[absolute local path](\\image.png)'),
+    )
     def test_absolute_win_local_path(self):
         self.assertEqual(
             self.get_rendered_result(['index.md']),
-            '<p><a href="\\image.png">absolute local path</a></p>'
+            '<p><a href="\\image.png">absolute local path</a></p>',
         )
 
     @mock.patch('mkdocs.structure.pages.open', mock.mock_open(read_data='<mail@example.com>'))
@@ -849,5 +800,5 @@ class RelativePathExtensionTests(unittest.TestCase):
             # The following is equivalent to: '<p><a href="mailto:mail@example.com">mail@example.com</a></p>'
             '<p><a href="&#109;&#97;&#105;&#108;&#116;&#111;&#58;&#109;&#97;&#105;&#108;&#64;&#101;'
             '&#120;&#97;&#109;&#112;&#108;&#101;&#46;&#99;&#111;&#109;">&#109;&#97;&#105;&#108;&#64;'
-            '&#101;&#120;&#97;&#109;&#112;&#108;&#101;&#46;&#99;&#111;&#109;</a></p>'
+            '&#101;&#120;&#97;&#109;&#112;&#108;&#101;&#46;&#99;&#111;&#109;</a></p>',
         )
diff --git a/mkdocs/tests/structure/toc_tests.py b/mkdocs/tests/structure/toc_tests.py
index 591d4f7b..44c9a4b8 100644
--- a/mkdocs/tests/structure/toc_tests.py
+++ b/mkdocs/tests/structure/toc_tests.py
@@ -6,135 +6,166 @@ from mkdocs.tests.base import dedent, get_markdown_toc
 
 
 class TableOfContentsTests(unittest.TestCase):
-
     def test_indented_toc(self):
-        md = dedent("""
-        # Heading 1
-        ## Heading 2
-        ### Heading 3
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-            Heading 2 - #heading-2
-                Heading 3 - #heading-3
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 2
+            ### Heading 3
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+                Heading 2 - #heading-2
+                    Heading 3 - #heading-3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 1)
 
     def test_indented_toc_html(self):
-        md = dedent("""
-        # Heading 1
-        ## <code>Heading</code> 2
-        ## Heading 3
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-            Heading 2 - #heading-2
-            Heading 3 - #heading-3
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## <code>Heading</code> 2
+            ## Heading 3
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+                Heading 2 - #heading-2
+                Heading 3 - #heading-3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 1)
 
     def test_flat_toc(self):
-        md = dedent("""
-        # Heading 1
-        # Heading 2
-        # Heading 3
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-        Heading 2 - #heading-2
-        Heading 3 - #heading-3
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            # Heading 2
+            # Heading 3
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+            Heading 2 - #heading-2
+            Heading 3 - #heading-3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 3)
 
     def test_flat_h2_toc(self):
-        md = dedent("""
-        ## Heading 1
-        ## Heading 2
-        ## Heading 3
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-        Heading 2 - #heading-2
-        Heading 3 - #heading-3
-        """)
+        md = dedent(
+            """
+            ## Heading 1
+            ## Heading 2
+            ## Heading 3
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+            Heading 2 - #heading-2
+            Heading 3 - #heading-3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 3)
 
     def test_mixed_toc(self):
-        md = dedent("""
-        # Heading 1
-        ## Heading 2
-        # Heading 3
-        ### Heading 4
-        ### Heading 5
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-            Heading 2 - #heading-2
-        Heading 3 - #heading-3
-            Heading 4 - #heading-4
-            Heading 5 - #heading-5
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 2
+            # Heading 3
+            ### Heading 4
+            ### Heading 5
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+                Heading 2 - #heading-2
+            Heading 3 - #heading-3
+                Heading 4 - #heading-4
+                Heading 5 - #heading-5
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 2)
 
     def test_mixed_html(self):
-        md = dedent("""
-        # Heading 1
-        ## Heading 2
-        # Heading 3
-        ### Heading 4
-        ### <a>Heading 5</a>
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-            Heading 2 - #heading-2
-        Heading 3 - #heading-3
-            Heading 4 - #heading-4
-            Heading 5 - #heading-5
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 2
+            # Heading 3
+            ### Heading 4
+            ### <a>Heading 5</a>
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+                Heading 2 - #heading-2
+            Heading 3 - #heading-3
+                Heading 4 - #heading-4
+                Heading 5 - #heading-5
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 2)
 
     def test_nested_anchor(self):
-        md = dedent("""
-        # Heading 1
-        ## Heading 2
-        # Heading 3
-        ### Heading 4
-        ### <a href="/">Heading 5</a>
-        """)
-        expected = dedent("""
-        Heading 1 - #heading-1
-            Heading 2 - #heading-2
-        Heading 3 - #heading-3
-            Heading 4 - #heading-4
-            Heading 5 - #heading-5
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 2
+            # Heading 3
+            ### Heading 4
+            ### <a href="/">Heading 5</a>
+            """
+        )
+        expected = dedent(
+            """
+            Heading 1 - #heading-1
+                Heading 2 - #heading-2
+            Heading 3 - #heading-3
+                Heading 4 - #heading-4
+                Heading 5 - #heading-5
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 2)
 
     def test_entityref(self):
-        md = dedent("""
-        # Heading & 1
-        ## Heading > 2
-        ### Heading < 3
-        """)
-        expected = dedent("""
-        Heading &amp; 1 - #heading-1
-            Heading &gt; 2 - #heading-2
-                Heading &lt; 3 - #heading-3
-        """)
+        md = dedent(
+            """
+            # Heading & 1
+            ## Heading > 2
+            ### Heading < 3
+            """
+        )
+        expected = dedent(
+            """
+            Heading &amp; 1 - #heading-1
+                Heading &gt; 2 - #heading-2
+                    Heading &lt; 3 - #heading-3
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
         self.assertEqual(str(toc).strip(), expected)
         self.assertEqual(len(toc), 1)
@@ -147,13 +178,15 @@ class TableOfContentsTests(unittest.TestCase):
         self.assertEqual(len(toc), 1)
 
     def test_level(self):
-        md = dedent("""
-        # Heading 1
-        ## Heading 1.1
-        ### Heading 1.1.1
-        ### Heading 1.1.2
-        ## Heading 1.2
-        """)
+        md = dedent(
+            """
+            # Heading 1
+            ## Heading 1.1
+            ### Heading 1.1.1
+            ### Heading 1.1.2
+            ## Heading 1.2
+            """
+        )
         toc = get_toc(get_markdown_toc(md))
 
         def get_level_sequence(items):
diff --git a/mkdocs/tests/theme_tests.py b/mkdocs/tests/theme_tests.py
index 296540af..b4c71553 100644
--- a/mkdocs/tests/theme_tests.py
+++ b/mkdocs/tests/theme_tests.py
@@ -14,31 +14,33 @@ theme_dir = os.path.abspath(os.path.join(mkdocs_dir, 'themes'))
 
 
 def get_vars(theme):
-    """ Return dict of theme vars. """
+    """Return dict of theme vars."""
     return {k: theme[k] for k in iter(theme)}
 
 
 class ThemeTests(unittest.TestCase):
-
     def test_simple_theme(self):
         theme = Theme(name='mkdocs')
         self.assertEqual(
             theme.dirs,
-            [os.path.join(theme_dir, 'mkdocs'), mkdocs_templates_dir]
+            [os.path.join(theme_dir, 'mkdocs'), mkdocs_templates_dir],
         )
         self.assertEqual(theme.static_templates, {'404.html', 'sitemap.xml'})
-        self.assertEqual(get_vars(theme), {
-            'locale': parse_locale('en'),
-            'include_search_page': False,
-            'search_index_only': False,
-            'analytics': {'gtag': None},
-            'highlightjs': True,
-            'hljs_style': 'github',
-            'hljs_languages': [],
-            'navigation_depth': 2,
-            'nav_style': 'primary',
-            'shortcuts': {'help': 191, 'next': 78, 'previous': 80, 'search': 83}
-        })
+        self.assertEqual(
+            get_vars(theme),
+            {
+                'locale': parse_locale('en'),
+                'include_search_page': False,
+                'search_index_only': False,
+                'analytics': {'gtag': None},
+                'highlightjs': True,
+                'hljs_style': 'github',
+                'hljs_languages': [],
+                'navigation_depth': 2,
+                'nav_style': 'primary',
+                'shortcuts': {'help': 191, 'next': 78, 'previous': 80, 'search': 83},
+            },
+        )
 
     def test_custom_dir(self):
         custom = tempfile.mkdtemp()
@@ -48,8 +50,8 @@ class ThemeTests(unittest.TestCase):
             [
                 custom,
                 os.path.join(theme_dir, 'mkdocs'),
-                mkdocs_templates_dir
-            ]
+                mkdocs_templates_dir,
+            ],
         )
 
     def test_custom_dir_only(self):
@@ -57,14 +59,14 @@ class ThemeTests(unittest.TestCase):
         theme = Theme(name=None, custom_dir=custom)
         self.assertEqual(
             theme.dirs,
-            [custom, mkdocs_templates_dir]
+            [custom, mkdocs_templates_dir],
         )
 
     def static_templates(self):
         theme = Theme(name='mkdocs', static_templates='foo.html')
         self.assertEqual(
             theme.static_templates,
-            {'404.html', 'sitemap.xml', 'foo.html'}
+            {'404.html', 'sitemap.xml', 'foo.html'},
         )
 
     def test_vars(self):
@@ -85,10 +87,12 @@ class ThemeTests(unittest.TestCase):
         self.assertEqual(theme.static_templates, {'sitemap.xml'})
 
     def test_inherited_theme(self):
-        m = mock.Mock(side_effect=[
-            {'extends': 'readthedocs', 'static_templates': ['child.html']},
-            {'static_templates': ['parent.html']}
-        ])
+        m = mock.Mock(
+            side_effect=[
+                {'extends': 'readthedocs', 'static_templates': ['child.html']},
+                {'static_templates': ['parent.html']},
+            ]
+        )
         with mock.patch('mkdocs.utils.yaml_load', m) as m:
             theme = Theme(name='mkdocs')
             self.assertEqual(m.call_count, 2)
@@ -97,9 +101,7 @@ class ThemeTests(unittest.TestCase):
                 [
                     os.path.join(theme_dir, 'mkdocs'),
                     os.path.join(theme_dir, 'readthedocs'),
-                    mkdocs_templates_dir
-                ]
-            )
-            self.assertEqual(
-                theme.static_templates, {'sitemap.xml', 'child.html', 'parent.html'}
+                    mkdocs_templates_dir,
+                ],
             )
+            self.assertEqual(theme.static_templates, {'sitemap.xml', 'child.html', 'parent.html'})
diff --git a/mkdocs/tests/utils/babel_stub_tests.py b/mkdocs/tests/utils/babel_stub_tests.py
index 59cb35f0..722d3b32 100644
--- a/mkdocs/tests/utils/babel_stub_tests.py
+++ b/mkdocs/tests/utils/babel_stub_tests.py
@@ -3,7 +3,6 @@ from mkdocs.utils.babel_stub import Locale, UnknownLocaleError
 
 
 class BabelStubTests(unittest.TestCase):
-
     def test_locale_language_only(self):
         locale = Locale('es')
         self.assertEqual(locale.language, 'es')
diff --git a/mkdocs/tests/utils/utils_tests.py b/mkdocs/tests/utils/utils_tests.py
index 1a79fcf0..0cb8142f 100644
--- a/mkdocs/tests/utils/utils_tests.py
+++ b/mkdocs/tests/utils/utils_tests.py
@@ -45,7 +45,7 @@ class UtilsTests(unittest.TestCase):
             'index.markdown': True,
             'index.MARKDOWN': False,
             'index.txt': False,
-            'indexmd': False
+            'indexmd': False,
         }
         for path, expected_result in expected_results.items():
             is_markdown = utils.is_markdown_file(path)
@@ -85,7 +85,8 @@ class UtilsTests(unittest.TestCase):
             ('a', ''): 'a',
             ('a', '..'): 'a',
             ('a', 'b'): '../a',
-            ('a', 'b/..'): '../a',  # The dots are considered a file. Documenting a long-standing bug.
+            # The dots are considered a file. Documenting a long-standing bug:
+            ('a', 'b/..'): '../a',
             ('a', 'b/../..'): 'a',
             ('a/..../b', 'a/../b'): '../a/..../b',
             ('a/я/b', 'a/я/c'): '../b',
@@ -114,55 +115,67 @@ class UtilsTests(unittest.TestCase):
             'https://media.cdn.org/jq.js': [
                 'https://media.cdn.org/jq.js',
                 'https://media.cdn.org/jq.js',
-                'https://media.cdn.org/jq.js'
+                'https://media.cdn.org/jq.js',
             ],
             'http://media.cdn.org/jquery.js': [
                 'http://media.cdn.org/jquery.js',
                 'http://media.cdn.org/jquery.js',
-                'http://media.cdn.org/jquery.js'
+                'http://media.cdn.org/jquery.js',
             ],
             '//media.cdn.org/jquery.js': [
                 '//media.cdn.org/jquery.js',
                 '//media.cdn.org/jquery.js',
-                '//media.cdn.org/jquery.js'
+                '//media.cdn.org/jquery.js',
             ],
             'media.cdn.org/jquery.js': [
                 'media.cdn.org/jquery.js',
                 'media.cdn.org/jquery.js',
-                '../media.cdn.org/jquery.js'
+                '../media.cdn.org/jquery.js',
             ],
             'local/file/jquery.js': [
                 'local/file/jquery.js',
                 'local/file/jquery.js',
-                '../local/file/jquery.js'
+                '../local/file/jquery.js',
             ],
             'local\\windows\\file\\jquery.js': [
                 'local/windows/file/jquery.js',
                 'local/windows/file/jquery.js',
-                '../local/windows/file/jquery.js'
+                '../local/windows/file/jquery.js',
             ],
             'image.png': [
                 'image.png',
                 'image.png',
-                '../image.png'
+                '../image.png',
             ],
             'style.css?v=20180308c': [
                 'style.css?v=20180308c',
                 'style.css?v=20180308c',
-                '../style.css?v=20180308c'
+                '../style.css?v=20180308c',
             ],
             '#some_id': [
                 '#some_id',
                 '#some_id',
-                '#some_id'
-            ]
+                '#some_id',
+            ],
         }
 
         cfg = load_config(use_directory_urls=False)
         pages = [
-            Page('Home', File('index.md',  cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']), cfg),
-            Page('About', File('about.md',  cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']), cfg),
-            Page('FooBar', File('foo/bar.md',  cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']), cfg)
+            Page(
+                'Home',
+                File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+                cfg,
+            ),
+            Page(
+                'About',
+                File('about.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+                cfg,
+            ),
+            Page(
+                'FooBar',
+                File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+                cfg,
+            ),
         ]
 
         for i, page in enumerate(pages):
@@ -175,55 +188,67 @@ class UtilsTests(unittest.TestCase):
             'https://media.cdn.org/jq.js': [
                 'https://media.cdn.org/jq.js',
                 'https://media.cdn.org/jq.js',
-                'https://media.cdn.org/jq.js'
+                'https://media.cdn.org/jq.js',
             ],
             'http://media.cdn.org/jquery.js': [
                 'http://media.cdn.org/jquery.js',
                 'http://media.cdn.org/jquery.js',
-                'http://media.cdn.org/jquery.js'
+                'http://media.cdn.org/jquery.js',
             ],
             '//media.cdn.org/jquery.js': [
                 '//media.cdn.org/jquery.js',
                 '//media.cdn.org/jquery.js',
-                '//media.cdn.org/jquery.js'
+                '//media.cdn.org/jquery.js',
             ],
             'media.cdn.org/jquery.js': [
                 'media.cdn.org/jquery.js',
                 '../media.cdn.org/jquery.js',
-                '../../media.cdn.org/jquery.js'
+                '../../media.cdn.org/jquery.js',
             ],
             'local/file/jquery.js': [
                 'local/file/jquery.js',
                 '../local/file/jquery.js',
-                '../../local/file/jquery.js'
+                '../../local/file/jquery.js',
             ],
             'local\\windows\\file\\jquery.js': [
                 'local/windows/file/jquery.js',
                 '../local/windows/file/jquery.js',
-                '../../local/windows/file/jquery.js'
+                '../../local/windows/file/jquery.js',
             ],
             'image.png': [
                 'image.png',
                 '../image.png',
-                '../../image.png'
+                '../../image.png',
             ],
             'style.css?v=20180308c': [
                 'style.css?v=20180308c',
                 '../style.css?v=20180308c',
-                '../../style.css?v=20180308c'
+                '../../style.css?v=20180308c',
             ],
             '#some_id': [
                 '#some_id',
                 '#some_id',
-                '#some_id'
-            ]
+                '#some_id',
+            ],
         }
 
         cfg = load_config(use_directory_urls=True)
         pages = [
-            Page('Home', File('index.md',  cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']), cfg),
-            Page('About', File('about.md',  cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']), cfg),
-            Page('FooBar', File('foo/bar.md',  cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']), cfg)
+            Page(
+                'Home',
+                File('index.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+                cfg,
+            ),
+            Page(
+                'About',
+                File('about.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+                cfg,
+            ),
+            Page(
+                'FooBar',
+                File('foo/bar.md', cfg['docs_dir'], cfg['site_dir'], cfg['use_directory_urls']),
+                cfg,
+            ),
         ]
 
         for i, page in enumerate(pages):
@@ -233,14 +258,12 @@ class UtilsTests(unittest.TestCase):
     def test_reduce_list(self):
         self.assertEqual(
             utils.reduce_list([1, 2, 3, 4, 5, 5, 2, 4, 6, 7, 8]),
-            [1, 2, 3, 4, 5, 6, 7, 8]
+            [1, 2, 3, 4, 5, 6, 7, 8],
         )
 
     def test_get_themes(self):
 
-        self.assertEqual(
-            sorted(utils.get_theme_names()),
-            ['mkdocs', 'readthedocs'])
+        self.assertEqual(sorted(utils.get_theme_names()), ['mkdocs', 'readthedocs'])
 
     @mock.patch('importlib_metadata.entry_points', autospec=True)
     def test_get_theme_dir(self, mock_iter):
@@ -289,9 +312,7 @@ class UtilsTests(unittest.TestCase):
 
         mock_iter.return_value = [theme1, theme2]
 
-        self.assertEqual(
-            sorted(utils.get_theme_names()),
-            sorted(['mkdocs2', ]))
+        self.assertEqual(sorted(utils.get_theme_names()), sorted(['mkdocs2']))
 
     @mock.patch('importlib_metadata.entry_points', autospec=True)
     def test_get_themes_error(self, mock_iter):
@@ -315,29 +336,37 @@ class UtilsTests(unittest.TestCase):
 
         j = os.path.join
 
-        result = utils.nest_paths([
-            'index.md',
-            j('user-guide', 'configuration.md'),
-            j('user-guide', 'styling-your-docs.md'),
-            j('user-guide', 'writing-your-docs.md'),
-            j('about', 'contributing.md'),
-            j('about', 'license.md'),
-            j('about', 'release-notes.md'),
-        ])
+        result = utils.nest_paths(
+            [
+                'index.md',
+                j('user-guide', 'configuration.md'),
+                j('user-guide', 'styling-your-docs.md'),
+                j('user-guide', 'writing-your-docs.md'),
+                j('about', 'contributing.md'),
+                j('about', 'license.md'),
+                j('about', 'release-notes.md'),
+            ]
+        )
 
         self.assertEqual(
             result,
             [
                 'index.md',
-                {'User guide': [
-                    j('user-guide', 'configuration.md'),
-                    j('user-guide', 'styling-your-docs.md'),
-                    j('user-guide', 'writing-your-docs.md')]},
-                {'About': [
-                    j('about', 'contributing.md'),
-                    j('about', 'license.md'),
-                    j('about', 'release-notes.md')]}
-            ]
+                {
+                    'User guide': [
+                        j('user-guide', 'configuration.md'),
+                        j('user-guide', 'styling-your-docs.md'),
+                        j('user-guide', 'writing-your-docs.md'),
+                    ]
+                },
+                {
+                    'About': [
+                        j('about', 'contributing.md'),
+                        j('about', 'license.md'),
+                        j('about', 'release-notes.md'),
+                    ]
+                },
+            ],
         )
 
     def test_unicode_yaml(self):
@@ -383,15 +412,15 @@ class UtilsTests(unittest.TestCase):
             'baz': {
                 'sub1': 'replaced',
                 'sub2': 2,
-                'sub3': 'new'
+                'sub3': 'new',
             },
             'deep1': {
                 'deep2-1': {
                     'deep3-1': 'replaced',
-                    'deep3-2': 'bar'
+                    'deep3-2': 'bar',
                 },
-                'deep2-2': 'baz'
-            }
+                'deep2-2': 'baz',
+            },
         }
         with open(os.path.join(tdir, 'base.yml')) as fd:
             result = utils.yaml_load(fd)
@@ -411,8 +440,8 @@ class UtilsTests(unittest.TestCase):
         ]
         dst_paths = [
             'foo.txt',
-            'foo/',             # ensure src filename is appended
-            'foo/bar/baz.txt'   # ensure missing dirs are created
+            'foo/',  # ensure src filename is appended
+            'foo/bar/baz.txt',  # ensure missing dirs are created
         ]
         expected = [
             'foo.txt',
@@ -459,7 +488,9 @@ class UtilsTests(unittest.TestCase):
                 os.chmod(src, stat.S_IRUSR)
                 utils.copy_file(src, dst_dir)
                 self.assertTrue(os.path.isfile(os.path.join(dst_dir, expected[i])))
-                self.assertNotEqual(os.stat(src).st_mode, os.stat(os.path.join(dst_dir, expected[i])).st_mode)
+                self.assertNotEqual(
+                    os.stat(src).st_mode, os.stat(os.path.join(dst_dir, expected[i])).st_mode
+                )
                 # While src was read-only, dst must remain writable
                 self.assertTrue(os.access(os.path.join(dst_dir, expected[i]), os.W_OK))
         finally:
@@ -492,9 +523,9 @@ class UtilsTests(unittest.TestCase):
                     'title': 'Foo Bar',
                     'date': '2018-07-10',
                     'summary': 'Line one Line two',
-                    'tags': 'foo bar'
-                }
-            )
+                    'tags': 'foo bar',
+                },
+            ),
         )
 
     def test_mm_meta_data_blank_first_line(self):
@@ -524,9 +555,9 @@ class UtilsTests(unittest.TestCase):
                     'Title': 'Foo Bar',
                     'Date': datetime.date(2018, 7, 10),
                     'Summary': 'Line one Line two',
-                    'Tags': ['foo', 'bar']
-                }
-            )
+                    'Tags': ['foo', 'bar'],
+                },
+            ),
         )
 
     def test_yaml_meta_data_not_dict(self):
diff --git a/mkdocs/theme.py b/mkdocs/theme.py
index 04ae3c4d..a83ac27a 100644
--- a/mkdocs/theme.py
+++ b/mkdocs/theme.py
@@ -56,8 +56,11 @@ class Theme:
 
     def __repr__(self):
         return "{}(name='{}', dirs={}, static_templates={}, {})".format(
-            self.__class__.__name__, self.name, self.dirs, list(self.static_templates),
-            ', '.join(f'{k}={v!r}' for k, v in self._vars.items())
+            self.__class__.__name__,
+            self.name,
+            self.dirs,
+            list(self.static_templates),
+            ', '.join(f'{k}={v!r}' for k, v in self._vars.items()),
         )
 
     def __getitem__(self, key):
@@ -73,7 +76,7 @@ class Theme:
         return iter(self._vars)
 
     def _load_theme_config(self, name):
-        """ Recursively load theme and any parent themes. """
+        """Recursively load theme and any parent themes."""
 
         theme_dir = utils.get_theme_dir(name)
         self.dirs.append(theme_dir)
@@ -107,7 +110,7 @@ class Theme:
         self._vars.update(theme_config)
 
     def get_env(self):
-        """ Return a Jinja environment for the theme. """
+        """Return a Jinja environment for the theme."""
 
         loader = jinja2.FileSystemLoader(self.dirs)
         # No autoreload because editing a template in the middle of a build is not useful.
diff --git a/mkdocs/utils/__init__.py b/mkdocs/utils/__init__.py
index 4006d1b7..17e52d19 100644
--- a/mkdocs/utils/__init__.py
+++ b/mkdocs/utils/__init__.py
@@ -30,12 +30,12 @@ markdown_extensions = (
     '.mdown',
     '.mkdn',
     '.mkd',
-    '.md'
+    '.md',
 )
 
 
 def get_yaml_loader(loader=yaml.Loader):
-    """ Wrap PyYaml's loader so we can extend it to suit our needs. """
+    """Wrap PyYaml's loader so we can extend it to suit our needs."""
 
     class Loader(loader):
         """
@@ -51,7 +51,7 @@ def get_yaml_loader(loader=yaml.Loader):
 
 
 def yaml_load(source, loader=None):
-    """ Return dict of source YAML file using loader, recursively deep merging inherited parent. """
+    """Return dict of source YAML file using loader, recursively deep merging inherited parent."""
     Loader = loader or get_yaml_loader()
     result = yaml.load(source, Loader=Loader)
     if result is not None and 'INHERIT' in result:
@@ -59,7 +59,8 @@ def yaml_load(source, loader=None):
         abspath = os.path.normpath(os.path.join(os.path.dirname(source.name), relpath))
         if not os.path.exists(abspath):
             raise exceptions.ConfigurationError(
-                f"Inherited config file '{relpath}' does not exist at '{abspath}'.")
+                f"Inherited config file '{relpath}' does not exist at '{abspath}'."
+            )
         log.debug(f"Loading inherited configuration file: {abspath}")
         with open(abspath, 'rb') as fd:
             parent = yaml_load(fd, Loader)
@@ -116,7 +117,7 @@ def get_build_date():
 
 
 def reduce_list(data_set):
-    """ Reduce duplicate items in a list and preserve order """
+    """Reduce duplicate items in a list and preserve order"""
     return list(dict.fromkeys(data_set))
 
 
@@ -181,7 +182,7 @@ def get_url_path(path, use_directory_urls=True):
     path = get_html_path(path)
     url = '/' + path.replace(os.path.sep, '/')
     if use_directory_urls:
-        return url[:-len('index.html')]
+        return url[: -len('index.html')]
     return url
 
 
@@ -255,7 +256,7 @@ def get_relative_url(url, other):
 
 
 def normalize_url(path, page=None, base=''):
-    """ Return a URL relative to the given page or using the base. """
+    """Return a URL relative to the given page or using the base."""
     path, is_abs = _get_norm_url(path)
     if is_abs:
         return path
@@ -288,14 +289,14 @@ def path_to_url(path):
 
 
 def get_theme_dir(name):
-    """ Return the directory of an installed theme by name. """
+    """Return the directory of an installed theme by name."""
 
     theme = get_themes()[name]
     return os.path.dirname(os.path.abspath(theme.load().__file__))
 
 
 def get_themes():
-    """ Return a dict of all installed themes as {name: EntryPoint}. """
+    """Return a dict of all installed themes as {name: EntryPoint}."""
 
     themes = {}
     eps = set(importlib_metadata.entry_points(group='mkdocs.themes'))
@@ -326,7 +327,7 @@ def get_theme_names():
 
 
 def dirname_to_title(dirname):
-    """ Return a page tile obtained from a directory name. """
+    """Return a page tile obtained from a directory name."""
     title = dirname
     title = title.replace('-', ' ').replace('_', ' ')
     # Capitalize if the dirname was all lowercase, otherwise leave it as-is.
@@ -402,7 +403,7 @@ def nest_paths(paths):
 
 
 class CountHandler(logging.NullHandler):
-    """ Counts all logged messages >= level. """
+    """Counts all logged messages >= level."""
 
     def __init__(self, **kwargs):
         self.counts = defaultdict(int)
diff --git a/mkdocs/utils/filters.py b/mkdocs/utils/filters.py
index c3049db9..d959784c 100644
--- a/mkdocs/utils/filters.py
+++ b/mkdocs/utils/filters.py
@@ -8,5 +8,5 @@ from mkdocs.utils import normalize_url
 
 @contextfilter
 def url_filter(context, value):
-    """ A Template filter to normalize URLs. """
+    """A Template filter to normalize URLs."""
     return normalize_url(value, page=context['page'], base=context['base_url'])
diff --git a/mkdocs/utils/meta.py b/mkdocs/utils/meta.py
index d208589d..714fb184 100644
--- a/mkdocs/utils/meta.py
+++ b/mkdocs/utils/meta.py
@@ -36,6 +36,7 @@ Extracts, parses and transforms MultiMarkdown style data from documents.
 
 import re
 import yaml
+
 try:
     from yaml import CSafeLoader as SafeLoader
 except ImportError:  # pragma: no cover
@@ -64,7 +65,7 @@ def get_data(doc):
         try:
             data = yaml.load(m.group(1), SafeLoader)
             if isinstance(data, dict):
-                doc = doc[m.end():].lstrip('\n')
+                doc = doc[m.end() :].lstrip('\n')
             else:
                 data = {}
         except Exception:
diff --git a/requirements/project-min.txt b/requirements/project-min.txt
index 00719753..7dc9825c 100644
--- a/requirements/project-min.txt
+++ b/requirements/project-min.txt
@@ -1,5 +1,5 @@
 babel==2.9.0
-click==3.3
+click==8.0
 Jinja2==2.10.2
 markupsafe<=2.0.1
 Markdown==3.3
diff --git a/requirements/project.txt b/requirements/project.txt
index 2e1be0c8..bcf8e8d3 100644
--- a/requirements/project.txt
+++ b/requirements/project.txt
@@ -1,5 +1,5 @@
 babel>=2.9.0
-click>=7.0
+click>=8.0
 Jinja2>=2.10.2
 Markdown>=3.3,<3.4
 PyYAML>=5.2
diff --git a/requirements/test.txt b/requirements/test.txt
index 9c4e8691..d38598f9 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -1,2 +1,3 @@
 coverage
+black
 flake8
diff --git a/setup.cfg b/setup.cfg
index 1e6ff981..41194d3a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,10 @@
 [metadata]
 license_file = LICENSE
 
+[flake8]
+max-line-length = 119
+extend-ignore = E203
+
 [compile_catalog]
 statistics = True
 domain = messages
diff --git a/tox.ini b/tox.ini
index e36af039..62799a82 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 envlist =
     py{36,37,38,39,310,py3}-{unittests,min-req,integration,integration-no-babel},
-    flake8, markdown-lint, linkchecker, jshint, csslint, nobabel, codespell
+    black, flake8, markdown-lint, linkchecker, jshint, csslint, nobabel, codespell
 
 [testenv]
 passenv = LANG
@@ -16,9 +16,13 @@ commands=
     py{36,37,38,39,310,py3}-unittests: {envbindir}/coverage report --show-missing
     py{36,37,38,39,310,py3}-integration: {envpython} -m mkdocs.tests.integration --output={envtmpdir}/builds
 
+[testenv:black]
+deps=-rrequirements/test.txt
+commands={envbindir}/black -l100 -tpy36 --skip-string-normalization mkdocs
+
 [testenv:flake8]
 deps=-rrequirements/test.txt
-commands={envbindir}/flake8 mkdocs --max-line-length=119
+commands={envbindir}/flake8 mkdocs
 
 [testenv:markdown-lint]
 whitelist_externals=